On Thursday the opposition Wafd newspaper said Gamal, son of ousted President Hosni Mubarak, had extensive holdings in the investment bank through foreign investment funds.

"EFG-Hermes Financial Group Holding stresses that its relationship with Mr. Gamal Mubarak is limited only to ownership of around 18 percent (which is the announced matter) in one of its subsidiary companies, EFG Private Equity," the bank said in a statement released by the stock exchange.

EFG-Hermes Private Equity contributes no more than 7 percent to the group's total revenue, the statement said, adding that the bank's relationship with Gamal dated to 1997, before he became involved in politics.

EFG-Hermes revenue in 2009 totalled 1 billion Egyptian pounds ($170 million), according to Reuters data.

Gamal Mubarak quit his position as head of the policy secretariat of Egypt's ruling National Democratic Party on Feb. 5. He previously worked as an investment banker for Bank of America in Cairo and London and helped set up another London-based advisory and investment firm.