Khan, who was ousted from power in April, has been in jail since August on charges of corruption and for allegedly disclosing the contents of a confidential cable sent by Pakistan's ambassador to the United States.
His lawyer, Naeem Panjutha, said the court had extended Khan's remand until Sept. 26.
The Federal Investigation Agency (FIA) is investigating Khan on charges of leaking the confidential cable to the media in order to damage Pakistan's relations with the United States.
Khan has denied the charges, calling them politically motivated.
He is also facing a separate corruption case in which he was sentenced to three years in prison in July. However, a high court suspended the sentence pending appeal.
Khan's arrest and detention have sparked widespread protests by his supporters, who have accused the government of trying to silence him.
The case is being closely watched by the international community, which is concerned about the rule of law in Pakistan. (ILKHA)