A Delhi court on Tuesday extended CBI custody of Chennai-based chartered accountant A Krishnamurthy and Indian Revenue Service official Anurag Vardhan, facing charges in the cash-for-transfer scam, till June 6 to enable the agency to interrogate them further.

Keeping in view the intricacies of the case and the racket that was alleged to have been going on over official transfers, Central Bureau of Investigation needs to be given more time to interrogate the accused, verify recorded conversation and confront the accused with it, Special Judge V K Jain said.

Seeking their custody, CBI counsel told the court that Vardhan had not yet disclosed the address of the owner of a car, which the agency claimed to have seized from his possession.

Recorded conversation between the accused reveal the names of nearly a dozen Income Tax officers who allegedly secured transfer by paying bribes, he said adding while some of them had been interrogated, many still needed to be questioned.

"The information is still only coming through," he claimed.