China has released Australian journalist Cheng Lei after more than three years, Prime Minister Anthony Albanese announced on Wednesday, adding she was freed and reunited with her two young children in Melbourne.

"The Australian people very much wanted to see Cheng Lei reunited with her young kids," Albanese said.

Cheng, a former anchor for state broadcaster CGTN, had been detained since August 2020. She was formally arrested months later and charged.

A statement by the Ministry of State Security in Beijing said Cheng was deported after serving her sentence.

A court in Beijing convicted her of illegally providing state secrets abroad and she was sentenced to two years and 11 months, the statement said.

Foreign Ministry spokesman Wang Wenbin said the Chinese judicial system tried the case “in accordance with the law, fully safeguarding the rights enjoyed by the person concerned in accordance with the law.”

Cheng's release comes ahead of Albanese's planned visit to Beijing this year on a date yet to be announced.

Albanese’s government has been lobbying for the release of Cheng and another Australian held in China since 2019, Yang Hengjun. (Agencies)