An investigation by BBC Africa Eye and Panorama has revealed widespread sexual exploitation on tea plantations in Kenya owned by Unilever and James Finlay & Co. These plantations supply some of the UK's most popular brands, including PG Tips, Lipton and Sainsbury's Red Label.

The report shows little has changed since Unilever faced similar allegations more than 10 years ago. In response, Unilever launched a "zero tolerance" approach to sexual harassment as well as a reporting system and other measures, but the BBC investigation showed that cases reported through the company's systems went ignored.

Allegations reported to the BBC by more than 70 women include rape and demands for sexual favours in return for employment, in a region where jobs are hard to come by. Some of the women became infected with HIV following these abuses.

Unilever says it was "deeply shocked and saddened" by the allegations. The company sold its operation in Kenya while the BBC was secretly filming, and the new owner, Lipton Teas and Infusions, says it has "immediately suspended the two managers", and ordered a "full and independent investigation".

James Finlay and Co supplies Kenyan tea to Sainsbury's and Tesco supermarkets, as well as Starbucks.

Tesco said it takes the allegations "extremely seriously" and is in "constant dialogue" with Finlay's to ensure "robust measures" are taken.

Sainsbury's said: "These horrific allegations have no place in our supply chain." On Monday, it issued a revised, updated statement saying it will "take robust action to safeguard workers" in its "tea supply chain."

Starbucks also issued a statement on Monday, saying it was "deeply concerned" and has taken "immediate action" to suspend purchasing from James Finlay and Company in Kenya.

Kenya's parliament has ordered an inquiry into the allegations.