A grandmother claims she was "chased into a car park" by an "off-duty police officer and his girlfriend" for allegedly texting at the wheel.
Gwendoline Persse, from Stockport, Greater Manchester, said the alleged incident happened when she became lost as she drove to a retail park in Hyde.
The 56-year-old says she was using Google Maps on her phone which was mounted in a cradle, reports Manchester Evening News.
Gwendoline claimed she suddenly heard a car horn and shouting coming from a car which pulled up alongside her, before a woman allegedly shouted "open your f***ing window".
The internal affairs department of Greater Manchester Police is now investigating the claims.
The woman is said to have motioned to a man in the car - believed to be her off-duty police officer boyfriend - and apparently screamed: "You've been texting. He's a f*****g copper!
"I'm f***ng having you."
Gwendoline, who has two daughters and two grandsons, said: "All the while she was puffing on an e-cigarette,"
She claimed she had got lost on her way to B&M Bargains, and drove into the retail park before the cars were parked in bays beside each other.
Gwendoline claimed the "off-duty officer" got out of the car and told her: "You have broken the law several times."
"He said he was a police officer," she added. "He said I was in the wrong lane and that I was on my phone.
"I told him I wasn't and that I had just touched the screen because it had gone blank.
"He said he was going to ignore the driving offence and he was just going to do me for being on my phone, and that I would get it through the post.
"He said I'd be fined £600 and I would get six penalty points on my licence. She was still pacing up and down puffing on her e-cigarette.
"He told her to go into the shop and let him handle this. She was being so aggressive. His demeanour was okay.
"He was just doing what she told him. It was her who had been banging on the window of her car and screaming."
Gwendoline said that in her panic she lost her phone at the scene and that the officer allowed her to use his mobile to contact GMP to confirm he was a bona fide police officer. He allowed Gwendoline to take a picture of his warrant card, she said.
She added: "I wasn't sure whether it was a police officer or not because of the way they acted. He said he would do all the paperwork when he was back on duty."
Tearful Gwendoline, who says she has never had any endorsements on her driving licence, said: "What's going on is that there's been a big injustice here.
"They can't do that. She can't just shout at me and eff and blind because her boyfriend is a policeman in his day off. It's not right. The whole experience has knocked me for six.
"I don't think that should happen to anybody. I've never been in trouble with the law. I've been a good person all my life. He was a bit younger than her and I think he was trying to impress her."
A spokesman for Greater Manchester Police said Gwendoline's complaint was being investigated by its Professional Standards Branch.
The spokesman said they could not comment further.
