The BBC said Monday it has uncovered evidence of sexual exploitation on Kenyan tea plantations that supply some of Britain's most popular brands.

In a video posted on the BBC World website, a supervisor on a Kenyan tea farm is seen with an undercover reporter and he asks her to touch him and undress.

He did not know he was being taped and a BBC crew was nearby for the reporter's protection.

More than 70 women told the BBC that that they had been sexually exploited by their supervisors on farms owned by Unilever, Lipton and James Finlay & Co. The companies supply some of Britain's most popular brands, including PG Tips and Lipton.

Some women told the BBC that work is scarce and they felt that they did not have any options.

On another plantation, the same undercover reporter attended an induction day for new recruits where a manager gave a speech saying the company had a zero-tolerance sexual harassment policy.

Afterwards, the manager invited her to meet him in a hotel bar that evening and suggested later that they go to his compound, the BBC reports.

Finley told the BBC that it has decided to investigate to determine if their Kenyan operation has "an endemic issue with sexual violence."

Lipton, which bought one of the plantations from Unilever while the BBC investigation was underway, has also launched an investigation.