Closed circuit camera footage at a toll booth, which could have provided clues regarding the persons who stole cars from Navi Mumbai for the Ahmedabad serial blasts, has so far been inconclusive, police officials said on Thursday.

Police officials had scrutinised the footage from cameras at the toll booths in Thane from where the cars are suspected to have been taken to Gujarat.

"We are still investigating the matter but so far nothing conclusive has been established," an official from the Anti-Terrorism Squad of the police said.

Four cars were stolen from Navi Mumbai a fortnight before the serial blasts in Ahmedabad [Images], two of which were used in the blasts and the other two were found loaded with explosives in Surat [Images].

The police had questioned employees of the Regional Transport Office and are also tracking gangs of car thieves in Mumbai and Navi Mumbai but so far, no arrests have been made in the case.