A British Airways flight to Ghana was grounded at London's Heathrow Airport for four hours after bed bugs were found crawling on the seats.

The cabin crew had walked out minutes before the scheduled take-off when they discovered the bed bug infestation, reported The Sun newspaper on Sunday (Jan 14).

A replacement plane was found and passengers were able to continue their journey only some four hours later.

A source told The Sun: "The cabin crew saw bedbugs crawling over the seats - visible to the naked eye.

"They said it was unacceptable to work on that aircraft."

In a statement to Yahoo News UK, an airline spokesman said: "The comfort of our customers is paramount, so as soon as this very rare issue was identified at Heathrow, we immediately took the aircraft out of service for treatment."

This is the latest in a string of bed bug infestation incidents to hit British Airways in recent months.

In October last year (2017), a Canadian family complained of multiple bites from bed bugs after a nine-hour flight from British Columbia to Britain.

The airline later apologised and gave the family an upgrade for their return trip.

In end-December, British news portal Daily Mail reported that a man was covered in dozens of bed bug bites after taking a flight in British Airways business class.

The airline has also received flak for poor customer service and cutting perks, such as free in-flight meals and alcohol for domestic and short-haul trips in economy class.