A Rex Airlines aircraft had to be evacuated after the crew were originally alerted to flames coming from the left-hand engine during the start-up sequence.

Regional turbo-prop flight, Rex Airlines flight ZL3937 was on the bay at Melbourne airport preparing for its Melbourne-King Island-Burnie flight when the crew was alerted.

"In accordance with standard operating procedures, the engine start sequence was aborted and the passengers evacuated," a Rex Airlines spokesperson said.

"The passengers were evacuated from an emergency exit which has no stairs.

"There is no requirement for stairs to be in place when using this emergency exit.

"The exit used was correct given the circumstances."

The spokesperson said all passengers were accommodated on a later service departing Melbourne at 6.15pm on Tuesday.

This aircraft was the not the same plane that was forced to turn around and return to Burnie airport on January 23, after reports of smoke coming out of the cockpit.