Two United Airlines pilots were arrested on suspicion of being under the influence of alcohol in Scotland on Saturday as they were about to fly to the United States, police and the airline said.

Police Scotland said the two men, aged 35 and 45 years, were detained under a section of the Railways and Transport Safety Act which covers carrying out pilot function or activity whilst exceeding the prescribed limit of alcohol.

The men are expected to appear in court in Paisley, near Glasgow, on Monday.

The flight from Glasgow to Newark Airport, New Jersey, carrying 141 passengers, eventually took off nearly 10 hours late on Saturday evening with a new crew, the airline said.

United said two pilots had been removed from service and their flying duties.

"We're collaborating with the authorities and will conduct our own investigation," said spokeswoman Erin Benson.

"The safety of our customers is our highest priority."

The pilots were arrested in the cockpit shortly before the 9:00 a.m. local time (4:00 a.m. ET) flight to the New Jersey airport was due to depart, the BBC reported.