A motorist is being investigated by police after she boasted on Twitter that she had knocked a cyclist off his bike.

Emma Way tweeted on Sunday: "Definitely knocked a cyclist off his bike earlier - I have right of way he doesn't even pay road tax #bloodycyclists." Her post prompted outrage among users of the social network, who alerted police to it. Norwich police contacted Way via Twitter saying "@emmaway20 we have had tweets ref an RTC [road traffic collision] with a bike. We suggest you report it at a police station ASAP if not done already & then dm [direct message] us."

Norfolk police subsequently said they were in touch with both Way and the cyclist involved, Tom Hockley, and were making further enquiries. Hockley was identified after he responded to Way's tweet by posting a message to her Facebook page. He wrote: "Oh hi! That was me you hit and FYI, you didn't knock me off, I'm too hard to be hurt by a pissy micra or whatever it was you were driving."

The 29-year-old freelance chef, from Norwich, later told BBC Norfolk that he had not intended to report the incident until he read the comment on Twitter.

He was on the 100-mile Boudicca Sportive ride in Norfolk on Sunday, about five miles from the end of the route, when he was struck by a car and flung into a hedge, he said. "A car came tearing round the blind corner and narrowly missed a cyclist in front of me," said Hockley.

"She came on to my side of the road. I took the wing mirror off and I went flying off my bike into a hedge. She hit me hard, really hard. I am lucky to be alive. But I managed to get out of the hedge and stand up. The car was nowhere to be seen. She hit me and she was gone. All I know is that it was a blonde girl driving."

He nevertheless finished the course after some roadside repairs to his bike. Hockley said of the comments on Twitter: "I think she came across as a very silly girl and made herself look like a bit of a fool."

Way's Twitter account has since been deleted but a number of people sent screengrabs to the police of other purported postings by her, including a photograph of a speedometer registering 95mph.

Ian Fitch, deputy managing partner of Larking Gowen, where Way is a trainee accountant, distanced the firm from her behaviour. "We most certainly do not condone this behaviour," he said. "We are taking the incidents very seriously. A full and detailed investigation will be carried out and appropriate action taken. We have already spoken to Norfolk police."

• This article was amended on 24 May 2013. The original incorrectly described Emma Way as a trainee solicitor.