The government reserves the right to file an appeal against the High Court's decision," Foreign Minister Shah Mahmood Qureshi told reporters on the sidelines of an international security conference in Munich on Sunday.

Qureshi said the release of Khan from effective house arrest was due to the Islamabad High Court's order and not an "executive decision".

72-year-old Khan, who was put under house arrest in 2004 by then President Pervez Musharraf after the scientist admitted having passed nuclear know how to North Korea and Iran, was released by Islamabad High Court on Friday.

Since the court issued its order, the top Pakistani leadership has been insisting that Khan has already been relieved of his duties and has nothing to do with the country's nuclear-related policies and nuclear programme.

Prime Minister Yousuf Raza Gilani has also said that Khan's proliferation network has been dismantled. Qureshi has said Khan is no longer in a position to formulate or influence nuclear policy.

Khan retracted the confession last year and launched a legal battle to end the restrictions on his movement.

On February 6, the Islamabad High Court, responding to Khan's petition, said he was a "free citizen" following a secret agreement between the scientist and government.

The court also said the secret deal would not be made public in keeping with a request from both parties.

Security around Khan's house in a posh neighbourhood in the heart of Islamabad remains tight with intelligence operatives in plainclothes posted around it.

He cannot leave his residence or meet anyone.