"Faisal Abbasi was arrested while returning from Bannu last week," the security official said, referring to the northwestern town, which borders Pakistan's tribal area.

The suspect accompanied Faisal Shahzad, the Pakistan-American bomber, to Pakistan's northwest to meet militant leaders, said the officer, who spoke on condition of anonymity because the intelligence agency does not permit its operatives to be named in the media.

Abbasi was with Shahzad throughout his time in Pakistan, the officer said.

He said Abbasi worked for the government's Council of Islamic Ideology, which advises on Islamic affairs.

The secretary general of the council confirmed Abbasi had worked there but had been on “vacation” for the last three months.

Pakistan police arrested and charged three suspects earlier this month on suspicion of having links to Shahzad.

Islamabad police chief Bani Amin, identified the three suspects as Shoaib Mughal, Mohammad Shahid and Hanbal Akhtar.

He said the trio also had close links with Tehreek-e-Taleban Pakistan (TTP) leaders including Hakimullah Mehsud, whose organization has claimed responsibility for Shahzad's May 1 plot to bomb Times Square.

At the request of the United States Pakistan has opened an investigation into possible links between Shahzad and militant groups.

Shahzad is due to be sentenced in the United States on Oct. 5. He has pleaded guilty to the May 1 failed bombing.