One of the plane's passengers, Ms Lee Bee Yee, 43, said she detected a faint whiff of what smelled like gasoline about two or three hours into the flight.

"We were informed by the pilot that there was a leak, and that the plane would have to return to Changi Airport as it did not have enough fuel for the journey," said Ms Lee, who runs an e-commerce company.

According to Ms Lee, the plane touched down safely at Changi Airport at around 6.45am to cheers and clapping from the passengers. Shortly after the landing, however, the plane's right wing caught fire.

"The blaze was quite fierce and we waited for around two to three minutes before the fire engines arrived," she said.

"Surprisingly, all the passengers were quite calm. The SQ crew was very professional in calming everyone down."