ST. JOHN'S, Antigua —  Antigua has formed a task force to investigate charges that the prime suspect in the U.S. sniper shootings illegally acquired an Antiguan passport and was selling the Caribbean country's passports to others.

Officials said on Monday that the four-person task force will investigate alleged passport fraud and racketeering by John Allen Williams, who changed his name to Muhammad when he converted to Islam.

"It is bad enough that Antigua has been associated with the suspected sniper John Allen Williams," Prime Minister Lester Bird said in a statement. It "is now very important that we ensure that our system for granting passports is as secure as possible."

If Muhammad was selling Antiguan passports and other documents, as neighbors and acquaintances have alleged, Bird said the investigation should determine how he got them.

Neighbors and acquaintances said Muhammad would arrange for birth certificates, Antiguan passports and other papers for Jamaicans wanting to emigrate to the United States.

To get his own Antiguan passport in 2000, Muhammad allegedly presented a falsified birth certificate.

Muhammad and fellow suspect, 17-year-old Jamaican John Lee Malvo. The two were arrested at a rest stop in Frederick County, Maryland, on Thursday.

Thom said authorities have confirmed that Muhammad arrived in the country as early as March 28, 2000, under the false name Thomas Lee Allen. It's not clear how long Muhammad lived on the island.