A ferry company operating in Britain has apologised after children were left “screaming” when an adult film was played on one of its ships from France to southern England.

Danish-based ferry operator DFDS has said it is “very sorry” after the incident, which happened on board the ferry from Dieppe in France to the British port of Newhaven.

It said that an “adult film” was mistakenly broadcast on the lounge television to passengers after watching a Formula One grand prix, causing children on board to be exposed to what one passenger described as “hardcore porn”.

A spokesperson said the incident took place during a delay, when the ferry was sent back to France because of a technical fault at Newhaven port.

A group of passengers asked if they could watch the Formula One grand prix on the TV in the on-board lounges, and the adult film played after the race.

DFDS said the crew were “not aware” that the film was due to be broadcast, adding: “Once the crew were alerted to the content, the channel was swiftly changed.”