Sainsbury’s has promised ‘robust action’ to safeguard workers in its supply chain after sexual abuse was uncovered at a tea farm owned by one of its suppliers in Kenya.

An investigation by the BBC found evidence of long-running sexual abuse at the farm, which is owned by British company James Finlay & Co, and provides tea for Sainsbury’s own-brand Red Label range.

More than 70 women told the BBC about abuse they’d experienced at the Finlays Kenya farm, and at another formerly owned by Unilever…