Hours after his capture, the authorities moved Omar to Peshawar, the capital of North West Frontier Province, for interrogation.

'In the initial probe he admitted that Baitullah Mehsud and more than a dozen other people died in the drone attack when he was at his father in law's house in South Waziristan,' said a second intelligence official aware of the investigations.

He said the Taliban were officially denying Mehsud's death in the missile attack earlier this month because they had so far not been able to agree on his replacement.

Pakistani and US authorities say they are almost certain about Mehsud's death, and claim the development has triggered bloody infighting among Taliban leaders over succession. The rebels have denied this.