A body found off the coast of Dubrovnik is that of missing Australian backpacker Britt Lapthorne, Croatian police have said.

Dubrovnik deputy police commander Ivan Kukrika told a press conference that DNA analysis had confirmed the identity of the body.

"DNA analysis has been completed in the capital, Zagreb," Kukrika said.

"According to the analysis, the body found in the sea on October 6th belongs to the missing Australian Britt Lapthorne."

Ms Lapthorne, 21, from Melbourne, was last seen at a Dubrovnik nightclub in the early hours of September 18.

Questions unanswered

Dubrovnik police crime squad chief Nikola Sakic said investigations were continuing into what happened to the Royal Melbourne Institute of Technology (RMIT) student.

"We still wait for the complete results of the analysis and therefore it is too early to say about the cause of the death," Sakic told reporters.

A local fisherman found the body in a cove near the town centre on Monday.

Ms Lapthorne's father Dale and brother Darren are in Dubrovnik, having travelled to the coastal tourist town in a bid to find her after she went missing.

Her mother Elke stayed in Melbourne.

Inaccurate reports

Croatian police had previously said the body was unlikely to be Ms Lapthorne because it was too badly decomposed.

On Thursday, a detective assigned to the case from Zagreb told the family reports that the remains were those of a young female between 150 and 160 centimetres tall with blonde hair were incorrect.

Ms Lapthorne was 152cm tall with blonde hair.

In a similar case three years ago, Croatian police said a body found in the sea had probably been there for several months before it was confirmed to be that of murdered British backpacker Peter Rushton.

Mr Rushton had vanished just five weeks earlier.