The father of a Melbourne girl missing in Croatia has said his daughter was a seasoned traveller who was cautious when she met new people.

Britt Lapthorne, 21, of Melbourne was reported missing after last being seen by friends at the Latin nightclub Club Fuego just outside the gates of the Old Town in Dubrovnik on September 18.

A search is now under way for Lapthorne, with a Department of Foreign Affairs and Trade (DFAT) spokesman confirming consular staff were helping authorities and Croatian police.

Worried friends have launched a campaign on social networking site Facebook to help find Lapthorne, a RMIT student in international business, who had deferred her studies for a semester to travel in Europe.

Her father Dale Lapthorne told TNT Magazine from Melbourne his daughter had lived overseas before and has spent the past few months travelling in eastern Europe.

Mr Lapthorne and his wife Elke have requested anyone who may have seen their daughter in Dubrovnik to contact police or DFAT.

“She is very bubbly, extremely organised and very careful with her possessions,” Mr Lapthorne said.

“She is quite recognisable, short and slight build, with her platinum bob.”

It was extremely out of character for her not to be in contact with her family and friends, he said.

Mr Lapthorne added her bank accounts hadn’t been accessed since she went missing. It is believed she was wearing black leggings and possibly denim shorts over the top of them the night she went missing.

Her brother Darren, a professional cyclist based in Germany, is heading to Croatia to assist in the search for Britt.

Anyone who has any information regarding the disappearance of Britt Lapthorne is urged to contact DFAT on +61 2 6261 3305 or Dubrovnik police.