19/10/2016 8:54 AM AEDT | Updated 19/10/2016 8:54 AM AEDT

Bishop Warns Of Long Wait For Crown Detainees In China

Three Australian casino employees are some of 18 in custody

Nick Ansell - WPA Pool/Getty Images
Foreign Minister Julie Bishop says two of three Australians in Chinese detention are in

CANBERRA – Foreign Minister Julie Bishop has confirmed two of three Australians detained on suspicion of committing "gambling crimes" last week in China are safe and well but the condition of the third citizen is unclear.

The employees of Australia's largest casino operator, James Packer's Crown Resorts, were swept up in a wider group of 18 employees who were taken into custody last Thursday and Friday.

Following concerns expressed by Packer and Prime Minister Malcolm Turnbull, consular officials had an "extensive" visit in Shanghai on Tuesday with detained Crown executive Jason O'Connor and a colleague.

Bishop said the two men are in "good health" and "their wellbeing is being looked after", but she explained the third Australian in Chinese detention is a dual citizen who has not yet been seen by Australian diplomats.

"I understand there is still some clarification needed as to whether he was an Australian or Chinese passport that he entered upon," the Foreign Minister told reporters in Canberra.

"But we will seek consular access as and when we can under the consular agreement we have with China."

No charges have yet been laid against the men, but it's understood that China is concerned about Crown's strategy for luring Chinese gamblers to Australia.

The Foreign Ministry has stated the detentions were conducted over suspected, unspecified "gambling crimes."

"Under Chinese law, the authorities can have 30 days to investigate allegations and then make a decision whether or not to charge," Bishop said.

"That period of 30 days can be extended by another seven days, I understand."

"In the meantime our focus is on their health and wellbeing and continuing to keep the families informed as we have been doing and also to carry out consular visits as and when we can."

Packer said Tuesday he is "deeply concerned" for the welfare of his staff and has stated his company Crown Resorts is doing all it can to ensure they are safe.

Crown runs three casinos in Macau, the rich autonomous territory known as the 'Vegas of Asia'.