The controversy centers on a memo in which Pakistani civilian officials allegedly sought U.S. help to prevent a possible military coup in exchange for Pakistani concessions.
Haqqani is accused of drafting the memo with the knowledge and approval of President Asif Ali Zardari.
Both men deny any involvement, but Haqqani resigned last month and opposition politicians asked the Supreme Court to look into the matter.
The Supreme Court announced on December 1 that it had set up a commission which was expected to complete its probe in three weeks.
In a statement on December 1, Haqqani said he had not been informed of a court order barring him from leaving the country, but that he had no plans to travel abroad in any case.
compiled from agency reports