US Senators concerned for Pakistan's former envoy Husain Haqqani

Fearing that Pakistan's former envoy to US Husain Haqqani may "become a political tool for revenge", three top American Senators have voiced concern over his treatment upon his return home.

Haqqani, accused of drafting the controversial Memogate note, was sacked after he was recalled to Pakistan to explain the document.

"We are increasingly troubled by Ambassador Haqqani's treatment since he returned home to Pakistan, including the travel ban imposed on him," Senator John McCain, Joseph Lieberman and Mark Kirk said in a joint statement, adding he they are closely following the case.

"We urge Pakistani authorities to resolve this matter swiftly and consistent with civilian rule of law," the statement said.

Islamabad should prevent the judicial commission probing Haqqani's case from "becoming a political tool for revenge against an honourable man", they said.

State Department spokesperson Victoria Nuland said though she had not seen the statement by the Senators commented that Washington wanted to see "any judicial proceedings go forward in a manner that is open, transparent, consistent with the highest standards of international justice."

A Pakistani commission set up to probe the incident has summoned Haqqani to testify as well as Pakistan's military intelligence chief Lt Gen Ahmed Shuja Pasha and former US National Security Adviser Gen James Jones.

The sacked envoy has denied allegations against him, telling a British daily the charges were part of a "psychological war" against him and that he feared for his life.