"I have done no crime whatsoever. My conscience is clear. I killed no one. I would not dream of doing it. I am not a monster - I am an ordinary, working-class, poor man," said Anthony Sawoniuk, 78.
He was being cross- examined about allegations that he led search-and-kill police squads to hunt down Jews escaping Nazi massacres in Belarus during the Second World War.
Mr Sawoniuk said prosecution witnesses had come to Britain to tell lies about him on the orders of the KGB, the former Soviet Union's secret police.
"Everyone is telling lies. They have been told by the Russian KGB to say there was a ghetto. Everyone is telling lies. These devils came here with their lies against me."
Mr Sawoniuk added that if they did not they would probably be imprisoned for "a few years" on their return.
John Nutting QC, for the prosecution, pointed out that one witness, Ben Zion Blustein, a Jew and boyhood friend of Mr Sawoniuk, now lived in Israel where there was no KGB.
The pensioner replied: "He has lost his brothers and sisters, so he comes here to give evidence.
"He does not care who is behind bars, so long as someone suffers."
Mr Sawoniuk, from south-east London, has denied two charges of murdering Jewish women while serving in the police force in his home town of Domachevo during the German occupation in 1942.
He was cleared of two other charges - alleging he murdered two Jewish males - last week on direction of the judge. He had denied them.
The trial continues today.