Hussain Haqqani, who served as ambassador to the United States, has filed a petition with the memo commission in Pakistan saying he is suffering from heart disease and cannot leave New York where he is undergoing an extensive medical exam, Pakistan's Dawn News reported Wednesday.
The former ambassador said he would return to Pakistan only after consultation with his doctors.
His earlier request to testify by video link has not been ruled on by Pakistan's Supreme Court.
Haqqani was labeled a traitor in Pakistan after Pakistani-American businessman Mansoor Ijaz alleged that the then-ambassador drafted a memo backed by President Asif Zardari that asked the U.S. government to help oust Pakistan's military leadership.
Both Zardari and Haqqani have denied any involvement in the alleged memo.