A Cypriot court on Friday launched extradition proceedings against a Chinese mother and son linked to US lobby groups, despite defence objections over a lack of official documentation, their lawyer said.

The mother, 61, and her son, 39, were arrested on December 8 under a warrant issued by Chinese authorities for alleged investment fraud in China between March 1, 2013 and March 31, 2014.

Defence lawyer Efstathios Efstathiou had called on the court to dismiss the extradition request at a pre-trial hearing on Thursday because the original documentation was not attached to the authorisation given by Cypriot authorities.

"The court, in an interim decision Friday, disagreed with our suggestion to reject China's request," Efstathiou told AFP.

The pair, who reportedly have the right of residency in Cyprus through investment, say they are being victimised for their political beliefs because of their involvement with right-wing lobby groups based in the United States.

The two Chinese nationals are free on 25,000 euros (over $28,000) bail each until their next court appearance.

The charges carry sentences of up to 10 years in prison.

A US organisation supported by former president Donald Trump's ex-adviser Steve Bannon had contacted Cypriot authorities to demand that the extradition request be rejected.

The lawyer confirmed the mother and son are members of the New Federal State of China, a US-based political movement lobbying against the Chinese government.

The group is tied to exiled Chinese tycoon Guo Wengui and Bannon, a China hawk.

The two also had links to another US group that lobbied against China, the Rule of Law Foundation.

The justice and interior ministries received a letter from the Rule of Law Foundation, an organisation aiming to "protect individuals speaking out against corruption and illegal activities in China", Politis daily said.

Lawyer Efstathiou said the Chinese suspects acquired Cypriot residency through investment seven years ago and have since applied for political asylum.

"They have requested international protection from the Republic of Cyprus due to well-founded fears of being treated unfairly due to their political beliefs," Efstathiou said.

Discrimination related to gender, religion or political beliefs are grounds for extradition not to be executed, he added.

Cyprus would prefer to keep the case low-profile as it has an extradition treaty with China and good diplomatic ties with Washington.

The extradition hearing is scheduled to start at Paphos district court March 2, when the prosecution will present its first witnesses.

The proceedings could take around 18 months because of their complexity.