The NAB investigators summoned Khawaja Asif on 11:00 am today at the bureau's office in Lahore in Iqama case.
He was also asked to bring along concerned documents with him during the appearance.
A petition had been filed in the SHC against the key PPP leaders Faryal Talpur, Manzoor Wasan, Nasir Hussain Shah, Sohail Anwar Siyal for allegedly holding work permits of a foreign country.
The SHC has reserved verdict on the petition after completion of arguments of lawyers.
The Sindh High Court (SHC) has adjourned the hearing of Iqama case against Pakistan People's Party's (PPP) leaders Faryal Talpur, Nasir Shah and others till December 6,