Police logbooks reportedly show Chief Whip Andrew Mitchell did call officers "plebs" and swore repeatedly during his furious outburst in Downing Street.
Unpublished records made by members of Scotland Yard's specialist protection team, which have been seen by The Sun newspaper, contradict the Tory enforcer's statement about the tirade he launched when he was stopped from cycling out of the main gates near No 10.
Senior coalition figures had called for a line to be drawn under the incident after the Sutton Coldfield MP apologised to the officer involved, but the documents will fuel speculation over his future in government.
It comes after Labour asked Downing Street's most senior civil servant to investigate the incident claiming, Mr Mitchell's account of the row was "unravelling by the day".
Police reports, made for senior officers, detail how the Tory was warned he would be arrested under the Public Order Act if he swore at the team again, according to The Sun.
The record is backed up by verbatim notes of the exchange made in the pocket books of two other officers, it said.
"The officers involved would have been happy to let the matter lie once Mitchell apologised," a source told the newspaper. "But their integrity is now being called into question by Mitchell's denials and that is totally unacceptable.
"Perhaps with the full verbatim report in the public domain, people can make up their own minds."