All of the passengers and crew from a helicopter that ditched in the North Sea have arrived safely back on land after air and sea rescues.

Fourteen people - 12 passengers and two crew - were on board the aircraft when it came down 25 miles off the coast of Aberdeen, shortly after midday.

Everyone on board was recovered from the sea and put in life rafts.

Nine men were flown to Aberdeen Royal Infirmary, while the remaining five were taken to Aberdeen by lifeboat.

One man is being detained at the hospital while all the others have been discharged or are not expected.

Consultant James Ferguson said: "All nine men admitted to the accident and emergency (A&E) department this afternoon are in good spirits and eight have been discharged.

"One patient has been kept in for observation as a precaution.

"We understand the remaining five on the lifeboat which arrived at Aberdeen Harbour have already been assessed and are not expected at A&E."

The EC225 Super Puma helicopter, operated by Bond Offshore, had been on its way from Aberdeen to the offshore Maersk Resilient rig and the Ensco 102 rig.

Rig operator Conoco Phillips said the passengers were contractors on their way to support the drilling rigs.

A Bond spokesman said: "A low pressure oil warning light came on and the helicopter made a controlled descent and landed in the North Sea. It didn't crash."

A major rescue operation was launched after the alarm was raised, with Coastguard and RAF helicopters called to the scene along with two lifeboats.

Scottish First Minister Alex Salmond said: "Incidents such as these remain very rare but do serve as a stark reminder of the dangers faced by those offshore workers who are required to use helicopters on a regular basis.

"Once all of those involved have been transferred ashore, the priority will be for the appropriate authorities to investigate the causes of this accident and ensure the future safety of flying operations in the North Sea."

The Aberdeen Royal Infermary where the the first passengers rescued from a helicopter that ditched in the North Sea have arrived. Credit: RNLI/PA

Jim McAuslan, general secretary of pilots' union Balpa, praised the helicopter's pilots, saying it "looks like a terrific piece of airmanship from very skilled pilots".

He said: "It is not for us yet to comment on the cause of this incident. That is for the AAIB (Air Accidents Investigation Branch) and we will await their findings."

He added: "We will be ensuring that the Civil Aviation Authority (CAA) look at the resulting AAIB report and put some effort into seeing whether any trends are emerging in North Sea helicopter operations."

But RMT union general secretary Bob Crow said the incident "shines the spotlight yet again on the issue of safety in our offshore industry".

Bond Aviation Group has announced it is suspending EC225 Super Puma helicopter flights until further notice for safety reasons following the incident.