A Chinese journalist arrested over a series of articles criticising a partly state-owned firm has appeared on public television to apologise, with state media saying he admitted the articles were "unverified and false".

Chen Yongzhou's newspaper, the New Express, had previously said it stood by the reports, but was not immediately available to comment on Chen's case, which made headlines around the world.

Appearing on Chinese state broadcaster CCTV on Saturday, Chen, wearing green prison uniform, looked into the camera as he apologised to the firm Zoomlion.

"I'm willing to admit my guilt and to show repentance. I offer sincere apologies to Zoomlion, which has suffered a loss, to the public trust of the news industry as well as to my family who all suffered. For the shareholders of Zoomlion ... I apologise too," he said.

"I did this mainly because I hankered after money and fame. I've been used. I've realised my wrongdoing."