Islamabad, Jun 2 (IANS): A former Inter-Services Intelligence (ISI) official, a key witness in the case in the murder case of former prime minister Benazir Bhutto, refused to testify against the Tehreek-i-Taliban Pakistan (TTP) suspects who are being tried.

An ex-telephone operator of the ISI excused himself from testifying before the court on Monday, saying that his life is in danger as he lives in Khyber Pakhtunkhwa's Karak district, which is a stronghold of the TTP, Dawn online reported on Tuesday.

Consequently, the anti-terrorism court (ATC) discarded his earlier statement which he recorded before the team investigating Benazir's murder case.

The former official had confirmed to the investigating team that he intercepted the communication between the suspects and TTP terrorists.

Five suspects -- Aitzaz Shah, Rafaqat Hussain, Husnain Gul, Sher Zaman and Abdul Rashid -- are facing trial in the case.

Besides, former president Pervez Musharraf, former city police officer (CPO) Rawalpindi Saud Aziz and former superintendent of police Khurram Shahzad were also accused in the case.

Benazir, the 11th prime minister of Pakistan, was assasinated on December 27, 2007, while leaving a campaign rally at Liaquat National Bagh in Rawalpindi.

A gunman fired shots at her and explosives were also detonated near the vehicle killing at least 20 people.