A diplomatic row between China and France appears to be brewing following the arrest last week in Cambodia of a French national, who Beijing said must be extradited to China so he can shed light of an ongoing criminal probe.

Media reports have indicated that the Frenchman, identified as 52-year-old architect Patrick Devillers, was picked up from his home in Phnom Penh at the behest of Chinese authorities, who reportedly linked him with the murder investigation being conducted on Gu Kailai, wife of the high-profile Chinese politicain Bo Xilai.

Mr Bo was purged earlier by China's senior leaders on accusations of corruption, while Ms Gu was arrested and put behind bars on allegations that she had a hand in the mysterious death in 2011 of British national Neil Heywood.

A report by The Wall Street Journal on Wednesday said that Ms Gu, Mr Heywood and Mr Devillers were friends and their relationship was traced back in the early years of the 1990s.

But no confirmation on the matter was provided by Chinese authorities except on the official extradition request lodged by China for the French national, which was confirmed by Cambodia's Interior Ministry, according to Agence France Presse (AFP) on Wednesday.

Phnom Penh has also affirmed that it has an existing extradition agreement with Beijing but insisted too that Mr Devillers' deportation to China will greatly depend on the evidences that Beijing will present to Cambodian authorities.

"We are waiting for evidence from the party that requested his arrest ... We need evidence from China," Khieu Sopheak, a spokesman for the Cambodian Interior Ministry told AFP on Wednesday.

Mr Khieu also clarified that despite Mr Devillers being kept under Cambodian custody, "he did not commit any wrongdoing ... and if there is no clear evidence, he will be freed."

His comments were made following reports that France pressed on Cambodia to first establish the legal framework on why Mr Devillers, who has been a long-time Cambodian resident, is being extradited to China.

In a statement, Paris confirmed too that it has been advised about Mr Devillers' arrest last week and "the consul visited him immediately after his arrest and keeps visiting him every day since."

"We're very closely following this case," French Foreign Ministry spokesman Bernard Valero told The WSJ on Wednesday.

Mr Valero added that his office has "expressed our vigilance that no charge of any sort can be pressed against (Mr Devillers) if the juridical basis isn't clearly established."

Paris also hinted that Phnom Penh has pledged to provide official clarifications on the details surrounding the arrest of its citizen.

In Beijing, the country's Foreign Ministry has issued a brief advisory stating that the government will not release an official statement touching on Mr Devillers' case.

The ministry also remained mum on speculations that the recent visit of a ranking Foreign Ministry official to Cambodia was connected to the Frenchman's arrest.