The mayor of New York may have refused to meet London's mayor because of remarks he made to a Jewish reporter, London Assembly Conservatives said.
The mayor said a reporter was 'like a concentration camp guard'
Michael Bloomberg was "too busy" to see Ken Livingstone on his last New York visit, stated a memo allegedly prepared for the Greater London Authority (GLA).
It said this was in "possible relation to bad reputation among Jewish press".
However a GLA spokeswoman said the memo "had never been seen by the mayor nor any of his officials".
Mr Livingstone sparked a row in 2005 after he told Jewish Evening Standard reporter Oliver Finegold that he was "just like a concentration camp guard".
He was suspended from the mayor's office for four weeks as a result, but that suspension was overturned after a High Court appeal.
The memo on the issue was read out as senior GLA officers were questioned on the mayor's foreign trips on Wednesday.
They revealed that Mr Bloomberg has had no formal meetings with Mr Livingstone, despite being New York's mayor since 2002.
Conservatives on the London Assembly questioned GLA officials about the memo, which they said was prepared for senior GLA staff ahead of a visit to New York in January.
Mayor Bloomberg has never formally met Ken Livingstone
John Ross, the GLA's director of economic and business policy, said: "The situation which existed with New York is that following 9/11 they closed down their international activity.
"Mayor Bloomberg has been slowly re-increasing their international activity and in fact the Mayor of London is going to New York in May for a meeting on climate change."
Mr Livingstone said on Wednesday he has previously met Mr Bloomberg informally to discuss the 2012 Olympics.
Richard Barnes, deputy leader of the London Assembly Conservatives, said: "The documents produced by the mayor's own officers paint a truly worrying picture of the decision process.
"By not putting London before his own political beliefs, Livingstone has and will continue to damage London as a major world city."
A spokeswoman for the GLA said the memo was "not a document produced by any department of the GLA, it has not been approved by any body or responsible officer in the GLA, nor does it represent the policy of the GLA".
She said: "If this is the level of material that is being produced as 'evidence' it is because those raising it cannot deal with the success of the mayor.
"It shows they are desperate and simply scrabbling around for diversions."