NEW YORK • An engaged couple were removed from a United Airlines flight to Costa Rica , as the airline remained under scrutiny following outrage caused by a video last week of a passenger being forcibly removed from a flight.

The couple, who were en route to get married, said a federal marshal escorted them from the plane before take-off from Houston, Texas, last Saturday.

However, United denied this on Sunday, saying in a statement that neither a marshal nor other authorities was involved.

The couple "repeatedly attempted to sit in upgraded seating which they did not purchase and they would not follow crew instructions to return to their assigned seats," the airline said in a statement. "They were asked to leave the plane by our staff and complied," it added.

The statement from a United spokesman said the airline offered the couple a discounted hotel rate for the night and rebooked them on a Sunday morning flight.

But Mr Michael Hohl and his fiancee, Ms Amber Maxwell, told KHOU, a TV station based in Houston, that they tried to pay for upgraded seating and were denied, after finding another passenger sleeping across their seats.

After moving a few rows up within the economy cabin, flight crew denied their request to pay a supplement for the seats, which United sells as "economy plus", and told them to move back to their original seats, said Mr Hohl.

"We thought not a big deal, it's not like we are trying to jump up into a first-class seat," Mr Hohl told KHOU. "We were simply in an economy row a few rows above our economy seat."

The airline suffered a public relations disaster after a video emerged last week showing security officers dragging a bloodied passenger off an overbooked United Express flight in Chicago.

After the incident triggered international outrage, United chief executive Oscar Munoz apologised to the passenger, his family and its customers, saying United would no longer use law enforcement officers to remove passengers from overbooked flights.

REUTERS