The deputy governor of Norway's central bank has quit after being denied security clearance because he is married to a Chinese citizen. 

Jon Nicolaisen, whose wife lives in China, has been married since 2010. He had his term at the bank extended in April, having originally been appointed in 2014. 

In addition to taking part in setting monetary policy, Nicolaisen had been in charge of overseeing Norway's $1.2 trillion sovereign wealth fund, the world's largest.

However, he has now released a statement declaring his immediate resignation, while questioning the reasoning behind him being denied clearance.

He said: "The Norwegian Civil Security Clearance Authority informs me that the reason that I will not receive a renewed security clearance is that my wife is a Chinese citizen and resides in China, where I support her financially.

"At the same time, they have determined that there are no circumstances regarding me personally that give rise to doubt my suitability for obtaining a security clearance, but that this does not carry sufficient weight.

"I have now had to take the consequences of this."

In recent years, Norway has introduced stricter rules for the issuing of security clearances, making it difficult in many cases to get approval for anyone married to a person from a country with which Norway does not have security cooperation.

Central Bank Governor Oeystein Olsen said Nicolaisen's departure would be a big loss.

"I will miss Jon Nicolaisen in his post as deputy governor, where he performed his duties superbly as a close colleague and competent professional," Central Bank Governor Oeystein Olsen said in a statement.