The National Accountability Bureau (NAB) on the directive of the Supreme Court issued summons to Mr Sharif and his sons Hussain and Hasan -- to interrogate them in its Lahore office in connection with their offshore properties revealed by the Panama Papers case.
On July 28, the five-member bench of the Supreme Court had disqualified Mr Sharif for possessing a work permit in the firm of his son in the UAE.
The apex court had also directed the NAB to investigate money laundering and other corruption charges against Mr Sharif and his children, son-in-law Safdar and relative federal finance minister Ishaq Dar in light of the report of the Joint Investigation Team.
The NAB confirmed that Mr Sharif and his sons have been directed to appear before its Lahore office on August 18.
The NAB said that it will take up the reference against Mr Sharif's close aide Ishaq Dar on August 23 and summons has been issued to him.
Mr Sharif, however, has not yet decided to appear before the NAB.
"Nawaz Sharif is considering boycotting the NAB proceedings because he thinks it is very much likely that like the Panama Papers case he may not get justice in its case as well," a PML-N senior leader told PTI.
He said Mr Sharif has already expressed his concern over a Supreme Court judge who is supervising the NAB's investigation against him, fearing that he (judge) will ensure adverse verdict against him in the accountability court.
"Sharif will discuss the NAB summons with his confidants on Thursday before making a final decision about his appearance in NAB," he added.