Britain’s aviation regulator has sought clarification from Air India after a Boeing 787 Dreamliner departed London despite concerns over a potentially faulty fuel switch and was later grounded in India for safety inspections, news agency ANI reported.

According to Reuters, the UK Civil Aviation Authority (CAA) sent a letter to the airline on Tuesday, warning that regulatory action could be taken against Air India and its Boeing 787 fleet if a full response is not provided within a week.