The chief executive of share market operator ASX, Elmer Funke Kupper, has resigned, effective immediately.
Funke Kupper, who had steered ASX since October 2011, was previously the boss of gambling giant Tabcorp and sits on the Tabcorp board.
Last week, it was revealed that the Australian Federal Police are investigating allegations that Tabcorp was involved in foreign bribery in Cambodia.
"The ASX board accepted that Elmer wanted to direct his full focus to the investigations which may be made into the Tabcorp matter - and not have them interfere with the important role of leading the ASX," said ASX chairman Rick Holliday-Smith.
Tabcorp said it had accepted Funke Kupper's request for leave of absence from the Tabcorp board until the completion of the police investigation.
"The company appreciates Mr Funke Kupper's request which is in accordance with the highest professional and governance standards," Tabcorp said.
The investigation into Tabcorp relates to an alleged payment of A$200,000 to a business linked to family of Cambodian Prime Minister Hun Sen.
Tabcorp explored a business opportunity in relation to the Cambodian sports betting market in 2009 when some Asian countries were considering deregulating sports betting.
Tabcorp said last week that it chose not to pursue the opportunity and the business was never operational.
Tabcorp said it was co-operating with the police investigation.
Holliday-Smith will take the reins at ASX as executive chairman until a replacement for Funke Kupper is found.
Funke Kupper will be paid in lieu of the notice period in his contract plus the various incentive payments to which he is entitled.
Holliday-Smith said Funke Kupper was a strong leader during his time at ASX and had positioned the company well for future opportunities.