The pilot of a plane headed to New York inadvertently caused a terror scare overnight when he became trapped in the bathroom and recruited a man with a "thick foreign accent" to alert the co-pilot.

The Delta Airlines flight from Asheville, North Carolina, was circling above the La Guardia airport when the pilot decided to go to the toilet before landing, the New York Post reports.

However, he became trapped and banged on the door until a passenger sitting nearby heard the ruckus and came over to his aid.

The pilot explained his situation and told the passenger to alert the co-pilot.

But the co-pilot, who sounded shaken, was not convinced of the man's story.

"The captain disappeared in the back and uh... I have someone with a thick foreign accent trying to access the cockpit. I gotta deal with the situation," the co-pilot told air traffic control.

Even after the helpful man with the foreign accent gave the aviator a password to access the cockpit he remained unconvinced.

"What I'm being told is he's stuck in the [lavatory], and, uh, someone with a thick foreign accent is giving me a password to access the cockpit," he said.

Air traffic controllers also confused by the situation instructed the co-pilot to "just get on the ground".

However, not long after the pilot managed to free himself from the bathroom and explain the situation to his colleagues.

Fighter jets were alerted but the incident was resolved before they could take to the sky.

The FBI was there to greet the plane when it eventually landed about 6.30pm yesterday (local time).