The Chinese company planning a nuclear power station at Bradwell has refused to share security arrangements with British authorities, it has been revealed.

China General Nuclear Power Corporation (CGN) were met by inspectors from the UK nuclear regulator earlier this year, as part of the four year approval process for the reactor the company wants to build at Bradwell.

The Office for Nuclear Regulation (ONR) welcomed the “high level of expertise and commitment” shown by the Chinese, in a report acquired by The Guardian.

However, the state owned company said it could not provide authorities with details about the security measures used to protect its plant in Fangchenggang, China, which the new Bradwell site could be modelled on.

But the ONR insisted it was commonplace for foreign nuclear companies not to share sensitive documents around national security during the UK nuclear approval process and added that it was the arrangements for Bradwell that were relevant, not Fangchenggang.

A spokesman said: “It is routine for site security plans to be protected, and is not unexpected.

“It will in no way restrict our assessment of the UK the Chinese reactor design.”

Campaigners fighting against plans for a new power station at Bradwell say they are not surprised no information on the station plans have been revealed.

Responding to the news Professor Andy Blowers, from Blackwater Against New Nuclear Group, said: “While this is deeply worrying, it is not entirely surprising.

“As The Guardian comments, this is ‘a glimpse of UK nuclear regulation rubbing up against Chinese state secrecy’.”

Prof Blowers said there was a need for more information on the power station proposals.

He said: “In CGN’s consistent refusal to answer even basic questions about its proposals and in its unwillingness to share security information with regulators, the Bradwell GDA has got off to an unpromising start. If there is nothing to hide, then why hide it?

“Confidence in the integrity and independence of the process, never high, will rapidly diminish if local and public interests are kept at arms length.”