A Winnipeg woman says her sister is too frightened to talk publicly about when she was picked up by a male taxi driver who allegedly asked her to have sex.

Sherri Shorting spoke with CBC News on Friday on behalf of her younger sister, who said she isn't comfortable directly commenting on what happened to her in a Unicity Taxi cab early Thursday morning.

Sherri Shorting

Sherri Shorting says her sister is too frightened to publicly share her own story about being asked to have sex with a taxi driver Thursday. (CBC)

Shorting said her sister paid the driver a flat rate of $10 to take her to a convenience store.

"On the way back, he told her he'd give her back her $10 if she would have sex with him," she said.

Shorting said she and her fiancé learned of what happened as soon as her sister returned.

With the taxi still parked outside their home, Shorting said she told her sister to go back to the car and get the driver to repeat the offer so they could be doubly sure about what he was asking.

"As he was talking to her, he still wasn't paying attention to us and I took my phone and tried to be as discreet as I could," Shorting said.

"She said to him, 'You're telling me that if I go with you, you'll give me back my $10?' And he said 'Yeah,'" Shorting said, adding that she and her fiancé witnessed the proposition take place this time.

"But then when she said, 'My husband is at the door,' he looked over and then he rolled up his window."

The driver sped off, but not before Shorting took down his Unicity Taxi cab number. She called the company immediately and followed up again later in the day.

"It was the day supervisor and he told me there was nothing on file, that nobody had even called there," Shorting said.

"He said, 'There's nothing here on file that even says that he was ever there.' I said, 'No, he was here, he picked her up and dropped her.' I said, 'She paid with her debit card,' and he said, 'That changes everything' and he said he would have a look and found the transaction."

Manitoba Taxicab Board investigating

Shorting filed a police complaint shortly thereafter. The Manitoba Taxicab Board is investigating the case, board chairperson David Sanders confirmed.

"We have already pulled in the vehicle in question, downloaded the camera — which is in the car — to see what evidence is there," Sanders said. "I don't have a report on that, but that kind of thing is already underway."

Shorting said she wants other women who encounter similar incidents to be brave and file formal reports with police and cab companies.

"I don't want women to be afraid — they need to come forward," she said. "If it's a start for us, it could be many others and with their stories; we could do something."

The incident comes on the heels of several other complaints registered about inappropriate cab driver behaviour.

Some women from the North End of Winnipeg recently started offering safe rides through a group called Ikwe (Women helping women safe ride), a service that Shorting said she intends to use going forward.

"I'm not taking cabs anymore until it's addressed," she said.

Unicity Taxi did not respond to a request for comment as of late Friday afternoon.