A British Airways plane had to divert on a flight to North Africa following alleged drunken behaviour by two women passengers.
The pair, believed to be aged 50 and 43, reportedly tried to force their way into the cockpit on the flight from Gatwick to Tunis.
One passenger was reported as saying that the women threatened to kill the family of a stewardess.
The crew of the flight, which had left Gatwick on the afternoon of New Year's Eve, decided to divert to Lyon in France where the women were handed over to French police.
They spent the night in custody before being flown back to London on New Year's Day. BA said UK police were now looking into the incident.
A BA spokeswoman added: "Our customers and flying crew deserve a safe and enjoyable flight. We do not tolerate any disruptive behaviour on board our flights.
"Monday's BA2664 service was diverted following the disruptive behaviour of two female passengers."