New Delhi  - FBI Director Robert Mueller will be travelling to India to boost counter-terrorism cooperation between the two countries and hold discussions in connection with the November Mumbai attacks, a news report said Sunday.

Mueller is expected to arrive on Tuesday amid growing cooperation between the Indian and US intelligence agencies after the Mumbai assault carried out by the Pakistan-based Lashkar-e-Taiba militant group, which left over 170 people dead.

A major outcome of the collaboration has been tracking of telephone calls made by attackers from Mumbai to their alleged handlers in Pakistan.

Sources told the Times that an FBI operative had been waiting in Pakistan to get to interview the suspects being held there.

Mueller, in a speech in the US, said Steve Merrill, a special agent from the US embassy in New Delhi, was in Mumbai while terrorists were on the rampage inside the city's Taj hotel.

"Amid gunfire and explosions, he established lines of communication with his Indian and intelligence community counterparts, coordinated the arrival of our Rapid Deployment Team, and helped rescue trapped Americans inside the Taj Hotel," the report quoted Mueller as saying.

"No red tape, no turf battles - just first responders, standing shoulder-to-shoulder in a time of crisis," he said.

Mueller said the US investigators had "unprecedented access to evidence and intelligence".

Agents and analysts conducted more than 60 interviews, including that of the lone surviving attacker, Ajmal Kasab.

"Our forensic specialists pulled fingerprints from improvised explosive devices. They recovered data from damaged cellphones, in one case by literally wiring a smashed phone back together," Mueller said. dpa