A British Airways flight which had been aborted when a mobile telephone was discovered aboard the aircraft made it to New York hours late Monday, British Airways said.

Flight 179 from London was an hour into its flight Sunday when a cell phone started to ring. When no one admitted owning the phone, the pilot decided to return to London.

Paul Marston, the British Airways spokesman, said the fact that the no one could explain how the phone got on the flight made the situation particularly suspicious. Cell phones — along with all other electronic devices — had been banned from cabins on flights out of Britain since Thursday, when authorities said they had discovered a plot to blow up trans-Atlantic airliners.

The flight resumed after security checks, and arrived about seven hours late in New York.

"Nobody on the plane owned up to having the phone," Marston said, adding that it was possible, although unlikely, that the phone had been left aboard during a previous flight.

"If someone had admitted to having the phone, than I'm sure the flight would have continued," he said.

"It is a puzzle," he said. "We're continuing to investigate."