Bill Birtles from the ABC and Michael Smith from the Australian Financial Review were evacuated overnight after a diplomatic stand-off.

The saga began when Chinese state security officers visited the homes of both men last week.

The reporters sheltered in diplomatic compounds for several days after police demanded they answer questions about detained Australian television anchor Cheng Lei.

Chinese officials eventually allowed both men to leave the country after they agreed to be interviewed.

The pair flew out of Shanghai and landed in Sydney on Tuesday morning.

"It's very disappointing to have to leave under those circumstances and it's a relief to be back in a country with genuine rule of law," Mr Birtles said.

"But this was a whirlwind and it's not a particularly good experience."

Mr Smith is also glad to be home.

"The late-night visit by police at my home was intimidating and unnecessary and highlights the pressure all foreign journalists are under in China right now," he said.

AFR editor-in-chief Michael Stutchbury and editor Paul Bailey described their expulsion as disturbing.

"This incident targeting two journalists, who were going about their normal reporting duties, is both regrettable and disturbing and is not in the interests of a co-operative relationship between Australia and China," they said.

China's foreign ministry said the questioning of the men was a normal enforcement of the law which authorities had strictly adhered to during their investigations, Reuters news agency reported.

Labor's foreign affairs spokeswoman Penny Wong said it was regrettable and deeply unfortunate Australia no longer had credentialed journalists in China, for the first time since the 1970s.

ABC news director Gaven Morris plans to restaff the public broadcaster's China bureau as soon as possible.

"The story of China, its relationship with Australia and its role in our region and in the world is one of great importance for all Australians, and we want to continue having our people on the ground to cover it," he said.

The Media, Entertainment and Arts Alliance said China's treatment of the two Australian journalists was appalling.

"China's continued intimidation and harassment of foreign journalists, including Australians, represents a dramatic low point for the foreign media's relations with China," MEAA president Marcus Strom said.

Australian journalist Peter Greste, a lead campaigner for press freedom after being jailed in Egypt, said reporters should never be used as political pawns or hostages.

Professor Greste urged the Chinese government to allow the Australian journalists and other foreign correspondents to return without hindrance or harassment.

Australians are advised not to travel to China and anyone still in the country has been told to return home as soon as possible.

People are warned Chinese authorities have locked up foreigners accused of "endangering national security" and Australians may be at risk of arbitrary detention.

Foreign Minister Marise Payne said this advice remained appropriate and unchanged.

Senator Payne said the Australian government continued to provide support to Australian citizens detained in China, including Cheng Lei, who has been held in Beijing for several weeks without charge.

A Chinese foreign ministry spokesman on Tuesday said Ms Cheng is "suspected of carrying out criminal activities endangering China's national security".

"Compulsory measures have been taken and an investigation is underway by the relevant authority," Zhao Lijian told a media briefing in Beijing.

Australian Associated Press