The head of Australia's main stock exchange has resigned amid an investigation into allegations that a gaming firm he once ran made a bribery payment several years ago to the family of Cambodia's prime minister.

Australian Securities Exchange chairman Rick Holliday-Smith said Monday that CEO Elmer Funke Kupper was resigning, effective immediately. Funke Kupper has denied any wrongdoing.

The shakeup follows a report published last week by Australia's Fairfax newspapers regarding a 200,000 Australian dollar ($152,000) payment allegedly made by Australian gaming giant Tabcorp to a consulting company linked to Cambodian Prime Minister Hun Sen's family in 2010.

Funke Kupper was Tabcorp's CEO at the time and Tabcorp had been looking to launch an online gaming operation in Cambodia.