Scientists say Australia could be on the verge of making major breakthroughs in baffling missing persons cases.

Key points: Not all of the DNA information is automatically available on one national DNA database

Not all of the DNA information is automatically available on one national DNA database Consequently, Dr Dadna Hartman worries cases are remaining unsolved

Consequently, Dr Dadna Hartman worries cases are remaining unsolved Victorian database helps solve 1994 case of a missing man

The possible gamechanger? A more powerful search engine to link up various DNA databases scattered around the nation.

"Clunky at best" is how molecular biologist Dr Dadna Hartman described the current way of trying to match unidentified human remains with missing people.

Each state and territory has its own DNA collection, created by taking samples from the family of missing people and also from unidentified remains.

But not all of the DNA information is automatically available on one national DNA database.

As a result, Dr Hartman worries that cases are remaining unsolved and families left in anguish about the location of their loved ones.

"I am sure that some of our unidentified remains that we currently have here in Victoria belong to interstate cases," Dr Hartman said.

Victorian database helps solve 1994 case

Every year, almost 40,000 Australians are reported missing.

Most show up quickly, but about 2,000 people vanish for more than three months.

Others never return.

One case that has been solved through family DNA matching is that of Melbourne fishmonger Mark Jansen.

The 31-year-old disappeared on November 12, 1994 leaving behind two young daughters.

Sister Paula Bunting said her brother's disappearance "ruined our family".

"Especially for our poor mother, it destroyed her," Ms Bunting said.

Mark Jansen with his father who died never knowing his son's fate. ( Supplied: Jansen family )

Twenty years later, a chance discovery in bushland ended the family's torment.

A fire ripped through the isolated area near Marysville, north-west of Melbourne, in early 2014 and an excavator was sent to help rehabilitate the land.

In the process, a human skull was unearthed. Three other bones were later found.

The bones were taken to the Victorian Institute of Forensic Medicine and matched to Mark Jansen.

The breakthrough was possible because years earlier both his parents had been asked to provide DNA samples.

The samples allowed scientists at Dr Hartman's laboratory to match Mr Jansen's parents to a DNA profile generated from his bones.

The lab currently has 300 DNA profiles for missing people, created by taking DNA samples from their family members.

It also contains 40 unidentified remains from which DNA profiles have been developed.

The profiles are made possible by sophisticated technology which can replicate a single strand of DNA many times over.

Molecular biologist Dr Dadna Hartman says the advanced search engine will bring together DNA collections from around the nation. ( ABC News: James Hancock )

'Almost immediate' breakthroughs predicted

The Australian Criminal Intelligence Commission already operates a limited national DNA database.

In order to link unidentified remains to a missing person, the system needs a DNA sample from the missing person themselves, rather than their family.

But a new advanced search engine will allow matching to family members by bringing together all the DNA collections around Australia.

Once that happens, Dr Dadna Hartman is expecting breakthroughs in cold cases.

"We will have a number of cases that will be linked almost immediately to unsolved cases," Dr Hartman said.

"Then we'll see that over time, as more people provide samples, and as more remains are found, we'll be able to have additional links."

The Intelligence Commission says it plans to roll out the new technology in the next year.

Paula Bunting (L) and Starry Jansen say the discovery of their brother's body gave rise to a complex range of emotions. ( ABC News: James Hancock )

Discovery brings comfort but more questions

Mark Jansen's sisters know how life-changing the improved national DNA database could be.

His family searched for him locally and interstate.

Sister Starry Jansen said she visited clairvoyants for 15 years hoping they could provide answers.

Their brother had been living a double life as a loving family man who got caught up in a gambling ring.

Paula Bunting said her brother's life had spiralled out of control and the family believes he was murdered.

"By 31 he was at rock bottom, he had nothing, he owed a lot of money," Ms Bunting said.

"His wife had separated, things went bad for him."

By the time police delivered the grim news to his mother, his father had died, never knowing his son's fate.

The family has been left with a complicated mix of feelings — devastation and closure.

"As bad as it sounds, it was a very good thing that we found him."

"[Otherwise] We would still be wondering," Ms Jansen said.

Paula Bunting agrees the discovery provided a sense of resolution.

But she fears her brother's killer is still out there.

"We never expected him to be found ever, especially after this long," she said.

"We watch the news now and when they say a body has been found, we can have a sigh of relief it's not our brother."

"However, the case is still open, he was murdered and someone's done it."

Victoria Police said it is continuing to investigate Mark Jansen's death.