Anwar Majeed, owner of Omni Group, and his son Abdul Ghani Majeed were arrested by the Federal Investigation Agency (FIA) after they appeared before the apex court in connection with the case, The News reported.
An apex court bench headed by Chief Justice Saqib Nisar heard the case.
Majeed's lawyer sought pre-arrest bail for his client.
Chief Justice Nisar said it was FIA's discretion whether it arrests the suspects.
The hearing was adjourned after the court ordered the Majeed family to become part of the investigation.
The chief justice said the court intends to form a Join Investigation Team (JIT) and it would welcome anyone willing to argue.
Zardari, his sister Faryal Talpur, former Pakistan Stock Exchange chairman Hussain Lawai, Summit Bank Senior Vice-President Taha Raza are among those being investigated by a seven-member JIT led by FIA Additional Director General Najaf Mirza for allegedly facilitating 29 'fake' accounts in Summit Bank, Sindh Bank and United Bank Limited.
Zardari served as the 11th President of Pakistan from 2008 to 2013. He rose to prominence after his marriage to Benazir Bhutto in 1987.