Mehsud's funeral was performed Wednesday afternoon, a Taliban leader told DPA.

'Right now, a meeting of our 'shura' (an advisory council of Mehsud's group) is being held in Sararogha to choose his successor,' the aide said.

The missile strike, believed to have been carried out by a US unmanned 'drone' aircraft, struck the house of one of Mehsud's two fathers-in-law in South Waziristan, a tribal region near the Afghan border and a known hub of Al Qaeda and Taliban militants.

The strike came as Pakistani security forces were gearing up for a major offensive against Mehsud, who is blamed for dozens of terrorist attacks across the country and had been declared Pakistan's enemy number one.

Meanwhile, the US government has begun an investigation into whether Mehsud was killed, senior US officials have said.

US officials Thursday said both US and Pakistani teams were investigating the possibility, Wall Street Journal reported Friday.

'There is reason to believe that reports of his death may be true, but they can't be confirmed,' a US official was quoted as saying.

Mehsud was considered one of the most wanted Islamist extremists in Pakistan's western tribal regions, leading a large army of militants that have fought US and Pakistani forces on both sides of the Afghanistan-Pakistan border.

The US and Pakistan will conduct DNA testing on the body believed to be Mehsud's, using genetic samples taken from members of Mehsud's family, the report said.

Results could take anywhere from days to weeks.