Sharon Bush, the former wife of the president's brother, Neil, told British Columbia's Vancouver Sun media scrutiny and criticism of Jack Worthington was unfounded, as she dated him after her divorce and knew him well.

"He is a fine man, highly ethical, a man of high integrity," Bush said.

Bush said she was speaking out after a British tabloid discredited a media investigation launched more than a year ago by Vanity Fair magazine into the background of Worthington, who bears a strong resemblance to the Kennedy family.

Earlier this week, Worthington showed the Globe and Mail his U.S. passport showing his birth date was two years to the day before John Kennedy was assassinated in Dallas in 1963.

U.S. Sen. Ted Kennedy, D-Mass., reportedly has balked at providing any family members' DNA for testing as Vanity Fair requested.