A search is underway for an Australian woman missing in Croatia.

Britt Lapthorne, 21, of Melbourne, was last seen by friends at a nightclub in Dubrovnik on September 18.

A Department of Foreign Affairs and Trade (DFAT) spokesman on Thursday confirmed consular staff were helping authorities searching for Lapthorne with Croatian police, who were taking her disappearance seriously.

“Consular staff from the Australian Embassy in (the capital) Zagreb are liaising closely with local authorities who are actively searching for the woman,” he said.

“Consular staff from the Department of Foreign Affairs and Trade in Canberra are maintaining close contact with the woman’s family and with the Australian Federal Police and Interpol, and are providing consular assistance.”

Worried friends have launched a campaign on social networking site Facebook to help find Lapthorne.

Her parents, Dale and Elke Lapthorne, posted a message pleading for any information that might help locate her.

“If anybody has interesting/relevant information (it may not appear relevant to you but to the authority it could be) please forward to DFAT,” they wrote.

The creator of the Facebook page, Tara Reynolds, said Britt was last seen a week ago and described her disappearance as “earth shattering”.

“I started this group because anything is possible and there is always hope. ANYONE who is out there travelling in Croatia or Bosnia who met Britt or may know of her whereabouts PLEASE contact her mother (or me and I will pass the message on),” she wrote.

“I only knew her for a few weeks, but they were the best weeks of my life!”

Britt’s family expressed their concern for her safety in a statement they issued through DFAT.

“Our daughter Britt is missing in Croatia. We are naturally very concerned and hope that she will be found safe and as soon as possible,” the statement read.

“In the meanwhile, this is a difficult time for our family and for Britt’s friends.

“We do not want Britt’s situation to be sensationalised. We will not be saying anything further publicly for the time being and we ask the media to respect our privacy.”