Colin Firth "showed his usual cool" when a plane he was on was raided by armed police yesterday.

The Hollywood star was flying back from the Oscars in Los Angeles with his wife Livia and their two young sons, when two people attacked each other on the aircraft over an alleged theft.

The British Airways flight - that was at 30,000 ft. - radioed for an armed police response unit to sort out the ruckus, after cabin crew struggled to contain it.

According to eyewitnesses, Colin remained calm and collected amongst the brawl, and was more concerned for the welfare of his family, including Luca, ten, and eight-year-old Matteo.

"Passengers were in meltdown when it spiralled out of control. It was scary for flyers who feared for the safety of the flight," a British Airways source told British newspaper The Sun.

"Colin Firth showed his usual cool and was more concerned at the well-being of his wife and kids.

"It was far more dramatic than anything at the Oscars."

The police unit boarded the flight on arrival at Heathrow airport.

Passengers, including model Jodie Kidd, were kept in their seats as officers stormed the aircraft after landing.

Apparently, no arrests have been made but inquiries into the incident are on-going.