Update – 1.10pm: The Department of Foreign Affairs says its working actively on the ground to resolve the case.

The former soldier, who was detained along with two British nationals in Erbil, is understood to have been fighting against ISIS.

The acting Minister for Foreign Affairs Charlie Flanagan says he is monitoring the situation closely.

Earlier: An Irish man who had been in Syria fighting against Islamic State is being detained in northern Iraq.

24-year-old Laois man Joshua Molloy, as well as two British nationals, was arrested on Friday in Erbil.

It is understood they had entered the country illegally after their visas expired.

The Department of Foreign Affairs says the Irish government stands ready to provide consular assistance.

Hannah Lucinda Smith, Turkey correspondent with The Times, interviewed Joshua when he first arrived in Syria last year.

She outlined how he came to be arrested.

She said: “The northern Iraqi government has been tightening up its policy on foreigners going to join the Kurds in Syria and they are unable to cross the border legally into Iraq.

“They were waiting for some weeks at the border trying to cross illegally, and when they finally did they were arrested by the northern Iraqi security services.

“So they are now in a prison in Erbil, which is the capital of northern Iraq.”