A probe has found that a pilot's spilt coffee was behind the emergency landing of a United Airlines flight at Toronto's Lester B. Pearson Airport Monday night, when the liquid triggered an emergency hijacking call.

A Transport Canada investigation found that the commanding pilot accidently set off the emergency code after spilling coffee on the Boeing 777's radio equipment.

The flight, from Chicago to Germany, made the emergency landing at about 10 p.m. Monday night.

The plane landed without incident or injury to any of its 241 passengers.