Several former IRA members have been removed from 'no fly' lists in the United States, a former law enforcement official has said.

The men were removed in 2007, and it is believed it was connected to an incident where Senator Edward Kennedy at one point ended up on a no fly list because his name was similar to an IRA suspect.

The Boston Herald has also revealed that several people who are on the no fly list are allowed to travel after being identified. This allows the FBI to shadow suspected terrorists when they are in the U.S.

If a person removed from the list decides to travel, FBI and Transportation Security Administration (TSA) agents consult with each other,  extra flight marshals are assigned to monitor the person during the flight and their baggage is given high priority screening.