MUMBAI, India — As rivals India and Pakistan try to get oft-derailed negotiations on track, a familiar obstacle reappeared this week in the electronic form of David Coleman Headley.

The American-born militant of Pakistani origin has dominated the Indian media for two days with court testimony via video conference from an undisclosed location in the U.S., where he is serving a 35-year sentence for involvement in the 2008 terrorist attacks in this commercial hub.

Granted a pardon in India in exchange for testifying against another alleged plotter, Headley on Tuesday repeated his assertions that Pakistan's military spy agency, the Inter-Services Intelligence, or ISI, helped Pakistani militants carry out the attacks that killed more than 160 people in Mumbai.

Headley, who at one time lived in Chicago, where he was convicted in 2013, said he was working for the ISI as well as the Pakistani militant group, Lashkar-e-Taiba, that India blames for the attacks. He said he scouted the Taj Mahal Palace hotel, which was one of the targets, and passed video and photos to a Lashkar-e-Taiba leader as well as an ISI contact he called “Maj. Iqbal.”

Much of Headley's testimony repeated statements he made at his federal terrorism trial and in interviews he gave to Indian investigators in the U.S. But his re-emergence comes at an awkward time, as India and Pakistan — nuclear-armed rivals that have fought four wars against each other in the last 70 years — struggle to revive wide-ranging security, economic and political talks.

Pakistan denies involvement with terrorism and has cast doubt on Headley's credibility. When he moved from the United States to Pakistan in 2002 to train with Lashkar-e-Taiba, Headley was also working as an informant for the U.S. Drug Enforcement Administration.

India has long sought to have Headley testify to raise pressure on Pakistan to bring the perpetrators of the attacks to justice.

Zaki-ur-Rehman Lakhvi, whom Headley said was Lashkar-e-Taiba's operations commander, is free on bail in Pakistan where he awaits a long-delayed trial.

Hafiz Saeed, Lashkar-e-Taiba's spiritual leader whose speeches Headley said inspired him, has a $10?million U.S. bounty on his head but lives freely in the Pakistani city of Lahore.

On top of this, Pakistani officials this week said they had found no evidence to support India's claims that Jaish-e-Mohammed, a domestic militant group, was behind a deadly attack last month on an air base in northern India. The raid deflated hopes of better relations after Indian Prime Minister Narendra Modi made an unannounced visit to Pakistan to meet Prime Minister Nawaz Sharif in December.

Parth M.N. is a special correspondent. Special correspondent Aoun Sahi contributed from Islamabad.

shashank.bengali@tribpub.com