Andrew Mitchell has used the word "pleb" in private conversation, a Tory former Cabinet minister said - but he did not believe it was something the former chief whip would have said in public.
Michael Portillo suggested police officers might have picked the word as one that people would readily believe had been uttered by Mr Mitchell.
"I have heard him use that word in private conversation - the pleb word, I mean," Mr Portillo told BBC1's This Week. "I didn't believe he could have used it at the gates."
Pressed on whether he had heard Mr Mitchell use the word, he said: "I think I did, but not in a bad context.
"Some policeman thought 'Ah, that's a word that people will believe that Andrew Mitchell might have used'. But he wouldn't have used it in that context."
Mr Mitchell admits he launched into a foul-mouthed rant at police officers who said he could not ride his bicycle through the main Downing Street gate but denies their claims that he called them "plebs".
The Crown Prosecution Service is considering whether to bring criminal charges following a Scotland Yard investigation into claims that officers conspired against the politician.