Updated at 7.12pm with new details.

Passengers on a British Airways flight from Malta to London suffered hours of delay on Monday after their plane was prevented from taking off, first because of an undocumented passenger and then because of an undisclosed technical issue. 

Flight BA 2645 was due to depart for Gatwick Airport at 2.10pm. Although the passengers boarded normally, the plane was kept on the tarmac after officials noticed that a passenger who arrived on the airline's inbound flight did not have valid travel documents and had to be returned to the UK.

The frustrated passengers were kept on the plane, some of them occasionally going to the front to ask what was happening.  The situation appeared to have been resolved at 4.20pm when the plane started to taxi, ready for take-off.  

But a technical malfunction was then detected, further delaying departure, an airport spokesperson said. 

The passengers were disembarked as engineers tried to solve the problem, a  passenger told Times of Malta. 

The flight was later cancelled. It was not immediately clear to the passengers when they would be able to fly out.