A DNA test has confirmed that Afghan Taliban leader Mullah Akhtar Mansour was killed in a U.S. drone strike, Pakistan's interior ministry said Sunday, as the family of a driver killed in the strike sought legal action.

A DNA sample from one of the men killed in the U.S. drone attack was successfully matched with a close relative of Mansour, the interior ministry statement said.

American and Afghan officials had already confirmed Mansour's death, but Islamabad had declined to do so before the DNA test results.

Mansour had entered Pakistan from Iran using a false name and fake Pakistani identity documents on May 21, when his car was hit by the U.S. missile.

On Sunday, the family of his driver -- identified as Mohammed Azam -- filed a police case against unknown U.S. officials, seeking to press murder charges against them, police officer Abdul Wakil Mengal said.

The family maintains Azam's innocence, and describes him as the sole breadwinner and a father of four. They say they want justice.

The identity of the U.S. officials involved in the drone strike is unknown, and it was unclear if the charges will relate to those who ordered the attack or the U.S. servicemen who carried it out.

Azam's family may be seeking a trial in absentia and a symbolic victory or they may attempt to push for compensation.

Earlier this week, the Afghan Taliban unanimously selected Mullah Haibatullah Akhundzada as their new head.