A spokeswoman for BA said the plane was diverted before it was ordered back to London.
Flight 175 departed from Heathrow at 11:15am yesterday with 239 passengers on board and was three hours into its journey to JFK airport when the pilot received the order.
At 5:30pm the 747 landed back at Heathrow, where the passenger in question was taken off the plane to be questioned by police.
The plane was expected to take off again last night to take the rest of the passengers to their destination.
A BA spokeswoman said: "Three hours into the flight, the captain received a request from the US authorities to turn back to Heathrow.
"The US said a passenger would not be allowed to land in New York.
"The plane landed at 5:30pm whereupon the passenger and his luggage were offloaded and he was met by police on arrival. There was no threat to the safety of the aircraft or its passengers."
The passenger had not been identified last night and no explanation was given as to why the individual had been refused entry to the US.
The US has compiled watch lists and no-fly lists in the wake of the 11 September, 2001 terrorist attacks on New York and Washington.
Last year Yusuf Islam, the former pop singer Cat Stevens, was escorted off a transatlantic flight and denied entry to the US because he was named on one of the lists.