Fears are growing for Australian man Alek Sigley as diplomats were last night scrambling to confirm reports he had been arrested in North Korea.

The government has described it as a “very serious set of circumstances”.

“It has not been confirmed that Alek has been detained in the DPRK,” his family said in a statement on Thursday.

“The situation is that Alek has not been in digital contact with friends and family since Tuesday morning Australian time, which is unusual for him.”

It is not known why Mr Sigley, a 29-year-old Asian scholar and fluent Korean speaker, might have been detained.

One of Mr Sigley’s former teacher’s, Leonid Petrov, a visiting fellow at the Australian National University, said “it’s concerning, but we still don’t know any particular circumstances going on”.

He also said Mr Sigley’s digital footprint, including his Facebook page, had been shut down.

“He’s a very smart and intelligent young man,” Mr Petrov told Macquarie Radio.

“There’s no better friend of North Korea than Alek Sigley.”