Pakistan International Airline (PIA) said Sunday it would investigate allegations that a plane flew from Karachi to Saudi Arabia carrying seven extra passengers, but denied they stood in the aisles for the three-hour journey.

It was reported that the January 20 flight to Medina carried 416 passengers, seven more than its capacity of 409 including jump seats, in a serious breach of air safety regulations.

Pakistan International Airlines' spokesman Danyal Gilani said media reports that some passengers travelled standing “are exaggerated and baseless. It is not possible for anyone to travel like that in an aircraft, regardless of the duration of the flight.”

But he said: “The matter pertaining to the travel of more passengers than the booked load...is under investigation,” and the airline had ordered a “thorough probe into it, and all concerned are being questioned”.

“PIA is committed to ensure the safety of the passengers and cannot allow any incident to happen which compromises safety,” added Gilani.

It was the latest embarrassing incident for the airline, considered a global leader until the 1970s but plagued by controversies over recent years and saddled with billions of dollars of debt.

A PIA turboprop built by European manufacturer ATR plummeted into a mountain on December 7, bursting into flames and killing all 47 people on board.