The barbaric atrocities at Bucha were part of a deliberate Kremlin strategy carried out in part by the feared Wagner Group of mercenaries, intercepted Russian radio transmissions have revealed.
Germany's foreign intelligence service, the BND, has heard messages from Putin's forces discussing the brutal murder of civilians in the city of horrors outside Kyiv, which was recaptured by Ukraine over the weekend.
The transmissions have been linked to specific corpses seen in Bucha, with one soldier talking about how he and his colleagues shot dead someone on a bicycle, while another said: 'First question soldiers, then shoot them.'
The audio messages have been relayed to German parliament by the BND to further debunk baseless Kremlin claims that the bodies were staged by Ukraine after Russia withdrew from the city in a 'monstrous forgery', Spiegel reported.
The wiretap recordings also show that the Wagner Group was present in the city and played 'a key role' in the massacre, and that there are likely similar scenes of slaughter elsewhere in the country.
The shadowy military company which has been linked to a string of killings, rapes and war crimes around the world is known as Putin's private army which carries out his dirty work at an arm's length from the state.
Meanwhile, also in Ukraine, Russia has completed the pullout of 24,000 troops from Kyiv and Chernihiv in preparation for an expected major offensive in the Donbas, where civilians have been told it is their 'last chance' to flee before the onslaught.
Donetsk, Luhansk and Kharkiv in the east are now seeing the worst of the fighting following the Russian withdrawal from the center, while Mariupol remains under siege with 170,000 still trapped in the besieged city where the civilian death toll has risen to 5,000, including 210 children, the mayor said.
The BND recordings from Bucha indicate the atrocities were neither accidental nor carried out by individual out-of-control soldiers.
Messages show the troops regularly discussed the potential war crimes as if they were talking about their everyday lives.
The BND told German leaders this shows how the killings were normalised and part of a deliberate strategy intended to sow fear and terror among the civilian population.
Further recordings are being analysed by intelligence chiefs 'with great concern' which have not yet been pinpointed to a specific place in Ukraine.
But they indicate crime scenes similar to Bucha in other cities across the country, particularly around Mariupol which remains under heavy bombardment.
The new evidence has prompted two former German government ministers to submit a criminal complaint with federal prosecutors seeking the opening of a war crimes probe against Russian officials including Putin.
Former Justice Minister Sabine Leutheusser-Schnarrenberger and former Interior Minister Gerhart Baum said they want to use German laws allowing prosecution of serious crimes committed abroad to bring to justice those they consider responsible for atrocities in Ukraine.
Germany's application of the rule of 'universal jurisdiction' led to the first conviction of a senior Syrian official for crimes against humanity earlier this year.
Lawyer Nikolaos Gazeas, who compiled the 140-page criminal complaint on their behalf, said it targets not just the Russian leadership of President Putin and the 32 members of his security council, but also 'a whole series of members of the Russian military.'
While prosecutors at the International Criminal Court have also launched an investigation into possible war crimes in Ukraine, Gazeas said parallel probes in multiple jurisdictions made sense and could be mutually reinforcing.
'The law is a weapon in this situation,' said Baum, 'and we want to use it.'
Ukrainian authorities said the bodies of least 410 civilians have been found in towns around Kyiv, victims of what Volodymyr Zelensky said was a Russian campaign of murder, rape, dismemberment and torture.
Local officials say more than 300 people were killed in Bucha alone, and around 50 of them were executed.
Some victims had apparently been shot at close range and others were found with their hands bound.
Zelensky has accused Russia of interfering with an international investigation into possible war crimes by removing the bodies and trying to hide other evidence in Bucha.
'We have information that the Russian troops have changed tactics and are trying to remove the dead people, the dead Ukrainians, from the streets and cellars of territory they occupied,' he said during his latest video address.
'This is only an attempt to hide the evidence and nothing more.'
Survivors from the month-long occupation have started to describe their gruesome treatment at the hands of Putin's invading troops after the area was liberated.
Mykola, a 53-year-old resident, spent a month hiding in the cold and dark cellar of his apartment building with his wife after witnessing callous executions on the streets of his hometown.
He told ABC that when the Russians arrived, they killed all men aged under 50 and then ordered him to bury his friends within 20 minutes.
Two of his friends were shot in front of him and another was hit by a grenade, blowing his body to pieces, which lay untouched for days until Mykola was allowed to quickly gather his parts in a bag and bury them in a shallow grave to ward off the dogs.
Vanya Skyba told The Economist how Russians rounded up a group of builders, ordered them to strip naked and lie face down on the floor while their bodies and phones were searched for evidence of military tattoos or anti-Russian sentiment.
One of the men was killed as an example to make the group talk, forcing one of the men to admit he had been a member of Ukraine's territorial defence who had served in the Donbas, prompting the Kremlin thugs to execute him too.
The others were beaten and tortured until an order to kill was issued by a Russian saying: 'F***ing do them in.'
They were led to the side of the building and each shot, and Skyba took a bullet in the side which went through his body. He played dead on the concrete floor until he heard silence when he fled over a fence to a nearby home.
He was later found there by Russians from a different unit who believed his cover story he was the owner of the home, but they led him back to the cellar where he had been shot where he sheltered with a dozens woman and children until they were freed.
After the savage killings, locals said Putin's army occupied the dead civilians' homes, drinking their alcohol, partying and stealing their belongings.
Volodymyr Abramov, 72, was dragged from his home along with his daughter Iryna, 48, and her husband Oleg, 40, after they smashed through his front gates, opened fire and threw a grenade inside the building.
As he tried to put out the flames with a small fire extinguisher, he shouted for Oleg to come and help before a Russian soldier menacingly told him: 'Oleg will not help you anymore.'
Volodymyr's son-in-law had been forced to kneel and was shot in the head at point blank range without even asking him a question, Iryna said.
She told the BBC: 'They didn't ask anything or say anything, they just killed him. They only told him to take off his shirt, kneel down, and they shot him.'
Iryna found the soldiers calmly drinking water next to his disfigured corpse after the shooting, and Oleg's body remained there for a month before it was safe for the family to return from a relative's house nearby.
Yuriy Nechyporenko, 14, and his lawyer father Ruslan, 49, were cycling to the city's administration building on March 17 to receive aid when they were stopped by a Russian soldier.
Yuriy told the BBC: 'We told them that we weren't carrying any weapons and that we didn't pose any danger.
'Then my father turned his head my way, and that's when he got shot… He was shot twice in the chest, right where the heart is. Then he fell.'
The teenager was then shot in the hand causing him to fall to the ground where he was then shot in the arm. A third shot rang out, aiming for his head but the bullet went through his hood, and once the Russian left, he was able to get up and run.
Vladislav Kozlovsky, who returned to Bucha at the outbreak of war to care for his mother and grandmother, told The Telegraph how two men he knew had tried to escape through an abandoned glass factory but were found by the Russians. One was shot in the back of the head. The other had his cheek cut out before being shot in the heart.
Volodymyr Pilhutskyi, another Bucha resident, recounted how his neighbour was taken away by Russian troops because he was wearing military-style trousers which were deemed 'suspicious'. He was tortured and killed, Mr Pilhutskyi said, with burn marks from a flamethrower found on his body.
Ukrainian armed forces said they uncovered a Russian torture chamber, located inside a children's hospital that was also being used as a makeshift barracks.
Visiting the region on Monday, a shattered Zelensky denounced what he called 'genocide' by Russian forces, adding that 'we know of thousands of people killed and tortured, with severed limbs, raped women and murdered children … dead people have been found in barrels, basements, strangled, tortured.'
The Kremlin has denied any civilian killings, claiming the images emerging from Bucha are fakes produced by Ukrainian forces, or that the deaths occurred after Russian soldiers pulled out.
At a UN Security Council meeting, Moscow's ambassador rejected Zelensky's claims, saying the 'ungrounded accusations... are not confirmed by any eyewitnesses'.
But satellite photos taken while Bucha was still under Moscow's control show what appear to be bodies lying in streets where the dead were later found by Ukrainian forces and seen by journalists.
And multiple Bucha residents told AFP they had seen Russian soldiers killing civilians.
'Right in front of my eyes, they fired on a man who was going to get food at the supermarket,' said 43-year-old Olena, who declined to give her family name.
During a grim cleanup, the remains of partially burned bodies in black bags were lifted into a van, with officials telling journalists 'dozens of bodies' remained in apartments and in nearby woods.
Bucha first came under attack by Russian forces trying to push into Kyiv in the early days of the war, and was the scene of fierce fighting that left streets filled with the charred husks of dozens of tanks and armoured vehicles - as well as the bodies of their crew.
The city was fully under Russian control by early March and endured occupation by Putin's men until last week when troops began withdrawing, having failed in their aim to assault the Ukrainian capital.
Over the weekend, Kyiv's men moved in to reclaim the region. It was during this time that the stories began to emerge.
