'Not right': woman's heartbreak over twin who vanished

Investigators initially believed Mr Breen had chosen to disappear on his own accord, but a recent review of the case made detectives believe he most likely met with foul play.

Police have revived an appeal for information surrounding his disappearance, a decision that has been welcomed by Mr Breen's family. 

"I always thought there was something not right," his twin sister Fiona said on Tuesday. 

"It's very hard. How can you explain how you feel when you don't know what's happened to him?"

Her fears were cemented when Mr Breen failed to attend his daughter's wedding about a month after he disappeared and again when he missed that same daughter's funeral in 2018. 

On Tuesday, police revealed his bank accounts and phone had never been accessed and there had been no reported sightings.

He was known to police and had previously been charged with fraud offences, spending several years behind bars.

The missing man went by several other names, including Brendan Green, Brian Greer and Brendan Lacombe.

Over the past 14 years, police have spoken to a range of Mr Breen's friends and associates in an effort to try and determine his whereabouts.

They have also sought information about who might be involved in his disappearance and any possible motivation for causing him harm.

Detective Inspector Dave Dunstan said several aspects of the case gave investigators cause for concern, especially the period of time Mr Breen had been missing "with no trace whatsoever".

"We know he had a number of associates who were also known to police and, while they have been spoken to over the years, this remains an active avenue of inquiry for investigators.

"While 14 years have passed, we strongly believe there are still people out there who know what has happened to Brendan, who is involved and why this has happened."

Police are also re-releasing images of Mr Breen in the hope they will assist people to come forward with information about his disappearance.