LAHORE - The fight between the Sharif family and the national anti-graft body has virtually intensified, as the NAB has summoned Hamza Shehbaz, son of Punjab Chief Minister Shehbaz Sharif, to appear before investigators in connection with the Saaf Paani scam.

An official said MNA Hamza was summoned by the National Accountability Bureau (NAB) on May 18 at the NAB headquarters in Lahore.

The move comes barely a few hours after ousted prime minister Nawaz Sharif came down hard on the NAB chairman over money-laundering claims. Nawaz demanded on Thursday that head of the anti-graft body prove allegations against him or step down within 24 hours.

The NAB authorities have been investigating corruption allegations in the Saaf Paani Company for the last several months. A few senior officers of the company have been arrested and they are in the custody of the anti-corruption body.

Political sources said Hamza will appear before the investigators. His father Shehbaz Sharif appeared before the NAB earlier and responded to various queries.

In the Saaf Paani case, some bureaucrats and political leaders too have been summoned by the NAB.

The Punjab chief minister has been asked to appear before NAB on June 4 in the same case.

NAB sources said that Hamza was summoned in Saaf Paani Company case because he used to attend official meetings illegally.