Three British Airways crew are being investigated for allegedly being under the influence of alcohol on duty.
BA say it is the fifth such incident in the past six years
The pilot, co-pilot and head of cabin crew were prevented from flying from Oslo to Heathrow on Tuesday morning after being reported by colleagues.
The 55 passengers had not boarded the 0745 GMT flight and were transferred to alternative flights to London.
BA, which has a zero tolerance policy on drugs and alcohol, said they face a disciplinary hearing.
Norwegian police said they all failed breathalyser tests.
Further blood tests have been taken and the results are expected in two weeks.
Norway's alcohol limit for pilots is 20 milligrammes in 100 millilitres of blood - the same as the country's drink drive limit.
They were questioned by police and released.
When they return to London they will face accusations of "gross misconduct" a BA spokesman said.
If found guilty they face instant dismissal.
The company said this was the fifth incident of its kind at the airline in the last six years.
BA captain Graeme Holden, of the Isle of Man, lost a claim for unfair dismissal in September, after BA dismissed him over a breach of its alcohol rules.
Another pilot, Simon Robinson of Wrecclesham, Surrey, was sacked in February for "gross misconduct", after being breathalysed before a flight from Sweden to London Heathrow.
The company's rules state crews should only consume alcohol in moderation in the 24 hours before reporting for duty.
They should not consume any alcohol in the last eight hours, and have no residual alcohol in their bloodstream when reporting for duty.
Civil Aviation Authority rules say aircrew cannot be on a plane or report for duty while drunk or under the influence of drugs.
The CAA says it will demand a full report from BA. It has the power to suspend or withdraw the licences of UK pilots.
There are 10,000 commercial pilots on the UK register, of which 12 to 15 a year lose their licences for alcohol offences - 85% of them later regain their licences after treatment and medical checks.
The law currently requires pilots not to be under the influence of alcohol while on duty, but there is currently no specified alcohol limit.
A new limit of 20 mg per 100 ml of blood - a quarter of the drink driving limit - is contained in the Transport and Safety Act passed earlier this year, but a date for introducing this new limit has yet to be set.