India Tuesday decided to extend the visa of Pakistani singer Rahat Fateh Ali Khan to facilitate the probe into the recovery of undisclosed foreign currency of over $100, 000 from him, even as Pakistan thanked New Delhi for releasing him.

"His visa has expired. His visa will be extended and we hope that post Feb 17 there could be adjudication proceedings, and we hope that the matter would be resolved, " Home Secretary G.K. Pillai told reporters here on the sidelines of a book release function.

The Directorate of Revenue Intelligence (DRI), which interrogated Rahat and others of his troupe, are continuing their investigation into the source of $124, 000 foreign exchange recovered from Rahat and two others -- Maroof, his manager, and Chitresh Shrivastava, the owner of an event management company.

The trio were detained at Delhi's Indira Gandhi International Airport Sunday night wh they were planning to catch a flight to Dubai for onward journey to Karachi.

Rahat was released Monday night after hours of interrogation by officials of the Directorate of Revenue Intelligence.

He was released after an assurance by the Pakistan High Commission that he will cooperate with the probe. The singer, along with two of his colleagues, have been asked to appear before the DRI on Thursday.

Pakistan Interior Minister Rahman Malik Tuesday thanked Home Minister P. Chidambaram for the release of Rahat and assured the latter of the singer's full cooperation in the probe.

Malik thanked Chidambaram for extending his assistance and cooperation in regard to the matter relating to qawwali singer Rahat Fateh Ali Khan, the Pakistan high commission said in a statement here. He also assured the Indian home minister of Rahat's full cooperation in the matter, in accordance with the law of the land, the statement added.

Government sources said India's external affairs ministry has been in constant touch with Pakistan's foreign office over the issue.

Rahat's release Monday night came amid intense pressure from Pakistan.

Pakistan's Foreign Secretary Salman Bashir called Indian High Commissioner in Islamabad Sharat Sabharwal and discussed the matter around midnight Sunday. He requested the Indian envoy to ensure that "no official should misbehave with Rahat during interrogation".

Bashir also called up Pakistani High Commissioner to India Shahid Malik and directed him to "take immediate steps for securing release of Rahat".