The counter-intelligence wing of the Andhra Pradesh police and the city police task force officials in Hyderabad have begun a probe into the antecedents of Habeeb Hasan, the man killed with Mumbai blasts key suspect, Nasir, on September 12 in an encounter in Mumbai.

"We were told that the second man hailed from Hyderabad, but we do not have any information about his antecedents so far. Our teams are verifying his background," Director General of Police S R Sukumara said. "Hasan was known to have gone to Gulf countries, but we are not clear about his intentions," he added.

Even as a special team of Mumbai police was scheduled to arrive here for investigations on Tuesday, city police sources said their preliminary inquiries have revealed that Habeeb Hasan, 26, was a maternal cousin of Nasir.

Hasan's sister is married to Mohsin, younger brother of Nasir. Mohsin stays in the United Arab Emirates.

Hasan's father Abdul Rehman Adroos worked as a taxi driver in Dubai for nearly three decades. Hasan worked as a security guard in a private firm in the UAE for some time and returned to India two years ago and started a computer training institute in Tadban area of the old city.

Recently, Hasan went to Mumbai to collect some papers required to send his sister to Yemen, where her in-laws are based.

Hasan's wife stays in his parents' house in Hyderabad.

Now, the police are probing Hasan's links, if any, with terrorist outfits and trying to ascertain whether he visited Pakistan for arms training.

Police claim that Hasan and Nasir were in Hyderabad on September 1, six days after the Mumbai blasts.

Hasan's house and his computer institute have been searched and some hard discs from the latter seized. They are questioning Adroos and other relatives of Hasan.

Police sources said Nasir was instigated by Hasan to avenge the killings of Muslims in Gujarat in post-Godhra riots.

The Hyderabad police are also investigating Nasir and Hasan's links with with Asghar Ali, the prime accused in the murder of former Gujarat home minister Haren Pandya.

Asghar Ali was arrested in Hyderabad on April 17 and is now lodged in a jail in Ahmedabad.