The investigation into the Salman Khan-Aishwarya Rai audio tape, in which the actor boasted of his underworld connections, may face hurdles with the Mumbai police commissioner today saying that the police did not have record of phone tappings of Salman's cell when it was under surveillance on suspicion of being used to talk to gangster Abu Salem.

"The record of conversations taped during surveillance is not maintained for four years. As per Supreme Court directions such tapes are regularly destroyed," Mumbai commissioner A N Roy told reporters here today.

According to Roy, the police had placed a cell phone under surveillance in August 2001 on the suspicion that it was being used to contact Salem. It was eventually found that the cell belonged to Salman, he said.

"We tapped the phone for two months after taking due permission, but at the end did not find anything suspicious," he said clarifying why the conversation tapes could have been destroyed then.

Roy, however, said that the ongoing probe will continue to find out if the purported audio tape was a police tape, and whether somebody leaked it.

The Maharashtra government has on Wednesday ordered a probe led by Additional CP, K L Bishnoi that would ascertain veracity of the alleged conversation, and check if Salman Khan indeed has underworld links.

Deputy Chief Minister R R Patil, who also holds the Home portfolio, had yesterday made a statement in the Legislative Assembly, where in he said that the state would take legal advise on the issue if required.