Image caption The ferry returned to port at North Shields after the fire

An investigation is under way after a fire on board a ferry in the North Sea forced it to return to Newcastle.

Police are questioning those on board, while a person suspected of starting the fire was detained by the crew.

RAF helicopters winched two passengers and four crew off the MS King Seaways, which was sailing to Amsterdam, when it was 30 miles off Flamborough Head.

The DFDS ferry, which had 946 passengers and 127 crew, returned to North Shields early on Sunday.

Insp Andrew Dixon of Humberside Police said the Maritime and Coastguard Agency (MCA) had called them at about 23:00 GMT and had said a passenger was "believed to have set fire to a cabin".

"As a result of this incident, the person suspected of causing the fire, or the person from the cabin where the fire occurred - be it deliberate or accidental - has been detained by ship staff," he added.

Some 15 passengers and eight staff were checked on the ferry by a doctor, DFDS added in a statement.

Media playback is unsupported on your device Media caption Ferry passenger Jamie Petterson: "Everyone was generally very calm"

It said the fire had started at about 22:45 GMT on Saturday but had been extinguished within 15 minutes.

Serge Chamuleau and his family, from Arnhem in the Netherlands, were on board the ferry.

He told BBC News: "We first discovered about the fire when we heard a loud noise that kept going for 10 minutes or so.

"We got out of the cabin to check what was going on and we were told about the fire by another passenger. We got dressed and the alarm signal was given and we had to go outside.

"There was a lot of smoke - you could smell it."

Gert Jakobsen, DFDS vice president, said the ferry had been boarded by police and fire investigators, who were speaking to crew members and passengers.

"The ship has arrived back in Newcastle and police are now on board and in control of it," he said.

"They are investigating the cause of the fire and speaking with senior crew members as well as passengers who were close to the incident."

Image caption Serge Chamuleau, a passenger, said he could smell smoke

Passengers have begun to leave the ferry.

Earlier, Steven Basford, one of the passengers, said: "We've been told we can't get off until the police have finished their investigation. They're going door-to-door so we just have to wait."

The 28-year-old from Northumberland, who had been travelling to Amsterdam with his partner to celebrate the new year with friends, described his experience of the fire alarm.

"We were in our room at about 10.40pm last night when they raised the general fire or emergency alarm with seven high-pitched siren noises," he said.

"We were told to evacuate outside the ship and when we got outside they asked us to converge around the lifeboats.

"The fire was on our floor but on the other side of the ship. When we climbed up to the communal area we could see the smoke. It wasn't thick but it was definitely noticeable.

"People were generally pretty calm."

The MCA said it would survey the vessel for any lasting damage.

Image caption An investigation is under way in to the blaze on MS King Seaways

The MCA's Jo Rawlings told BBC News that conditions for the rescue had been "fairly calm".

Those winched off the ferry had been airlifted to Scarborough and no-one was seriously injured, she said.

Helicopters from RAF Leconfield and RAF Boulmer were sent to the scene.

Sqn Ldr Dave Webster said that when the RAF had been called for assistance, it was initially thought 23 people would need to be winched to safety but that figure was later downgraded.

The RAF crew had lifted those affected off the ferry within an hour.

Ferry operator DFDS Seaways runs a daily 17:00 GMT service from North Shields, arriving in Ijmuiden, the Netherlands, at 08:30 GMT (09:30 local time).

According to its website, the 26-year-old MS King Seaways has room for more than 1,500 passengers and 600 cars. It was renovated in 2006.

It offers entertainment including restaurants, bars, a nightclub and a casino.