Chief Whip Andrew Mitchell "did swear in frustration", but not at the police who stopped him from cycling through the Downing Street main gate, reports suggest.
Mitchell apologised to police officers for being disrepectful, but denied calling one of them a "pleb" in his anger.
According to the Sunday Telegraph, Mitchell was frustrated at being denied entry through the main gate, and said: "Look, I'm the chief whip, I work at Number 9 (Downing Street). You guys are supposed to f****** help us."
A friend of Mitchell also told the paper: "It was in frustration at the episode and not aimed directly at the officers. It was the fourth time he had been at Downing Street that day - he is frequently allowed to use the main gate on his bike. He is absolutely not accusing anyone of lying."
The rant created a ruckus in political circles after the Tory enforcer was accused of swearing at a member of Scotland Yard's Diplomatic Protection Group.
The friend then went on to say: "He realises there may be differing versions of what was said but he is adamant he did not use the words he is reported to have used."
Mitchell earlier said he did not use any of the words attributed to him, but did not elaborate.
Cabinet Minister Ken Clarke came to the defence of Mitchell and said he was a courteous man. "I have known Andrew for a long time and he is a perfectly reasonable, courteous man with the same high regard for the police services as anyone else.
"He obviously had a flare of bad temper on this occasion and has rightly apologised. I do think this should be allowed to set the matter at rest."
As Labour called for an inquiry into the episode, Lib Dem President Tim Farron said the angry rant was "utterly, indeed beyond unacceptable".