Investigators in the United States and Trinidad are probing possible link between the alleged plot to blow John F Kennedy airport in New York and Iran.
Newsday quoted police sources in New York and Trinidad as saying that they are investigating whether one of the suspect, Imam Kareem Ibrahim, had ties to Iraq and Iran.
Former Guyanese law maker Abdul Kadir, 55, was arrested on Friday in Trinidad minutes before he was to fly out to Venezuela from where, sources told the paper adding he was to fly to Iran.
Three of the four suspects were arrested in Trinidad while the fourth was taken into custody in New York. Any link to Iran would heighten tension between Washington and Tehran, already at loggerheads over Iran's nuclear aspirations.
US Officials also fear the possibility of an Iranian militant presence in the Caribbean because of Iran's ties with leftist presidents in Venezuela and Nicaragua, Newsday said.
In Guyana, Police Commissioner Henry Greene told the paper that he was not aware of any Islamic radical elements.
Muslims comprise up to 15 per cent of the population of nearly 800,000. Most are East Indian Sunnis. It quoted relatives and friends of Kadir, 55, a Christian who converted to Islam while a college student in Trinidad in the 1970s, as saying he had connections to Iran and is a devout Shia. But they said he was not an imam, as US Court papers claim, and that he was far from radical.
"He is a progressive, not a fanatic," Marjorie McCaskey, a longtime friend, was quoted as saying.