Matthew Craig Barrett, 27, was remanded to judicial custody for 14 days by a court in Islamabad yesterday following his arrest from sector I-11 of Islamabad on Friday. He was then taken to Adiala Jail in Rawalpindi.
Police said the Interior Ministry had ordered him to leave Pakistan by June 4 and his continued presence in the country violated the Foreigners Act.
The Interior Ministry had written to the Additional Inspector General (Special Branch) of Islamabad to trace Barrett after he escaped from Fateh Jang area last month following a scuffle with security officials.
Fateh Jang is considered a sensitive area because several nuclear facilities are located there.
Barrett was "blacklisted" by the Interior Ministry, which cancelled his visa last month. Police said arrangements were being made to deport Barrett to the US at the earliest. Till the completion of his remand or arrangements for his deportation, Barrett will be held in Adiala Jail.
Security agencies had been on Barrett's trail for a long time following his visits to sensitive installations, including nuclear facilities, at Jhang Bahtar near Fateh Jang and other suspicious activities, media reports said.
Barrett had married a Pakistani woman from Islamabad three-and-a-half years ago. The couple have two children.
Born on 4 June 1984, Barrett belongs to Alabama state in the US. He has contended that he had done nothing wrong and was being made a victim of the strained ties between Pakistan and the US.