NEW DELHI, Oct 8: Director General of Pakistan’s Inter- Services Intelligence (ISI) Lt Gen Mahmud Ahmed has been replaced after the FBI investigators established credible links between him and Umar Sheikh, one of the three militants released in exchange for passengers of the hijacked Indian Airlines plane in 1999.

The FBI team, which had sought adequate inputs about various terrorists including Sheikh from the intelligence agencies, was working on the linkages between Sheikh and former ISI chief Gen Mahmud which are believed to have been substantiated, reports PTI website.

Informed sources said there were enough indications with the US intelligence agencies that it was at Gen Mahmud’s instruction that Sheikh had transferred 100,000 US dollars into the account of Mohammed Atta, one of the lead terrorists in strikes at the World Trade Centre on Sept 11, it adds.