By Maria Ward-Brennan Fast-fashion giant Boohoo has been hit with an investor lawsuit in the UK after reports alleging its suppliers were mistreating workers caused its share price to plummet in 2020. A report by The Sunday Times in 2020 revealed multiple alleged labour rights violations at its suppliers’ factories in Leicester, highlighting that some workers were paid as little as £3.50 an hour. The firm’s share price tanked after the expose was published, wiping more than £1.5bn off the online retailer’s market value. City A.M. can now reveal that law firm Fox Williams filed a lawsuit agains…