A US government attorney confirmed to BBC that Sadequee was supposed to be produced before the Federal Court in New York yesterday for his suspected involvement with Islamist militancy. An FBI special agent was supposed to officially press charges against him in the court.

A legal expert in New York in an interview with BBC was surprised by the news of Sadequee's extradition and said the US does not have any extradition treaty with Bangladesh. Consul General of Bangladesh in New York Kazi Imtiaz Hossain also confirmed to BBC that the US does not have any extradition treaty with Bangladesh. However, he declined to comment on how then Sadequee was extradited to the US.

A US attorney's office told BBC that there had been a warrant issued through Interpol for arrest of Sadequee and possibly he was extradited based on that warrant.

Meanwhile, Bangladesh government and the police authorities continue to keep mum about how Sadequee ended up in FBI custody.

Police officials concerned yesterday said he was abducted and the case is still under investigation. Asked about his whereabouts, top police officials at an exchange of views programme with journalists yesterday bypassed the question and suggested reporters to contact the police station concerned.

An AP news report posted on The New York Times website yesterday reported that Sadequee, 19, who is accused of making materially false statements in connection with an ongoing federal terrorism investigation, was arrested in Bangladesh and was en route to New York City to be arraigned.

Sadequee's father, Sarder Md Sharif, in Dhaka said the allegations against his son regarding involvement with militancy are totally baseless.

He also confirmed to BBC that his son is now in custody of FBI.

A top official of the US Embassy in Dhaka told BBC Bangla Service yesterday that they are not sure whether Sadequee was handed over to FBI.

However, Sharif yesterday told a news conference that the US Embassy in Dhaka asked him to send Sadequee's medicine and inhaler to them after they had come to know about his son's illness. He also said he had given those to them on Thursday.

The AP news report also said another US citizen of Pakistani origin, Syed Haris Ahmed, and Ehsanul Islam Sadequee traveled to Canada to meet with Islamic extremists to discuss 'strategic locations in the United States suitable for a terrorist strike', according to an affidavit made public Friday.

Ahmed and Sadequee, both of whom grew up in Atlanta area, met with at least three other targets of ongoing FBI terrorism investigations during a trip to Canada in March 2005, an FBI agent's affidavit said.

The affidavit also said the men discussed attacks against oil refineries and military bases and planned to travel to Pakistan to get military training at a terrorist camp, which the authorities said Ahmed then tried to do.

The AP report said Sadequee is accused of lying about a trip he made in August when he was interviewed at John F Kennedy International Airport as he was about to leave for Bangladesh.

The affidavit also said Sadequee had said he had traveled alone in January to visit an aunt.

When Sadequee's suitcase was searched at JFK, agents found a CD-ROM containing encrypted files that FBI has been unable to decode and a map of the Washington area hidden in the lining of the suitcase, the affidavit said.

One day later, federal agents interviewed Ahmed, who was coming back from a month-long trip to Pakistan, at Atlanta's Hartsfield-Jackson International Airport. He said he had gone to Toronto with Sadequee, according to the affidavit.

Federal agents found that money for both men's 2005 bus trip from Atlanta to Toronto was withdrawn from Sadequee's account, AP reported.