The man, of Lebanese descent, has only been identified by the initials TH.

He was reportedly arrested in a Lebanese Armed Forces raid on an apartment in Dahr al-Ain, just outside the troubled northern Lebanese city of Tripoli, the National News Agency reported on Monday.

The man arrived in Lebanon one month ago, an unnamed security source told the Daily Star newspaper.

Fairfax Media put a number of questions to the Lebanese military about the man's arrest but has yet to receive a response.

A Department of Foreign Affairs and Trade spokesman said Australian Embassy officials in Beirut were seeking to confirm with local authorities whether an Australian man had been arrested in Lebanon.

If the arrest was confirmed, the man would be offered consular assistance, the spokesman said.

Lebanon's second city of Tripoli has frequently been the site of deadly sectarian violence since the civil war began in neighbouring Syria.

Most recently, twin suicide bombings in the majority Alawite neighbourhood of Jabal Mohsen in January killed nine people and wounded more than 30, sparking another harsh crackdown by Lebanon security forces who are struggling to prevent the militant group Jabhat al-Nusra from gaining a foothold in the country's north.

Fighting between militants in Jabal Mohsen and neighbouring Sunni Bab al-Tabbaneh has killed dozens of people in recent years as the sectarian Syrian conflict increasingly spills over the border into Lebanon.

With Megan Levy