Fresh bid to solve mysterious disappearance of Aussie mum and her teen daughter after 25 years

The tormented family of a mother and daughter who disappeared 25 years ago have begged the public to share any information as police revive search efforts. 

Rosemary Brown, 33, and her 15-year-old daughter Melissa Trussell were last seen in Blair Athol, in north Adelaide, about 2.30am on May 13, 2000. 

Rosemary's handbag was found later that day on Stirling Street in the neighbouring Adelaide suburb of Northfield. 

Wednesday marked exactly 25 years since Rosemary's body was found among mangroves on Garden Island on July 2, 2000. 

Despite extensive searches and investigation, her daughter's body has never been found, and police believe she was murdered. 

No charges have ever been laid in connection with either case. 

Despite the passage of time, police believe they may be closing in on a breakthrough, aided in part by advances in DNA technology. 

'We're following some positive lines of inquiry but we can always have more information and sometimes it's those little pieces of the jigsaw puzzle that we're looking for to put it all together,' Detective Superintendent Darren Fielke said. 

Melissa Trussell, known as Melissa Brown, (pictured) was 15-years-old when she went missing. Police have never recovered her body

Rosemary Brown's (pictured) body was found among mangroves on Garden Island exactly 25 years ago on July 2, 2000

Melissa's father Barry Trussell asked the public to put themselves in his shoes. 

'The what ifs, you know, what sort of mother would she have been? What sort of life would she have led?' he told a press conference on Wednesday. 

'All these things are taken away from her and extra enjoyment we could've got out of life having her involved in our life.

'Any little bit of information you've got can help, no matter how small. It can be what breaks the case.'

Melissa's younger sister Kayla said the family had endured 'decades of pain' and described her sister as a happy, generous soul. 

'She was my best friend,' she said. 

'We would always play Barbies together, play ponies… I could pretty much make her do anything, I was just her little brat sister.'

Earlier this year, SAPOL released a new photo of Melissa in an effort to revive interest in her disappearance. 

Police suspect Melissa (pictured) was murdered, though her body has never been found

Rosemary had moved homes in the days before her disappearance after being evicted from the Windsor Gardens Caravan Park on May 3.

In addressing the public on Wednesday, Mr Fielke described the matter as a 'particularly disturbing' case.

'A mother was murdered and her body disposed of. We believe Melissa was also murdered,' he said.

'I have no doubt that numerous people either know what happened to Rosemary and Melissa or have information that will assist the investigation into their suspected murder.'

He said Rosemary's handbag was among those items expected to undergo further DNA analysis. 

Asked whether there was any chance Melissa could be alive, he said: 'I very much doubt it. Not after 25 years.

'Everything points to the fact that she's not alive. I'd love to say that she is but the reality is that it's highly unlikely that she is.'

He said a number of persons of interest had been identified and investigated over the years but said police had failed to find enough evidence to lay charges. 

'We don't believe... that it's a stranger. We think it's likely they are people that are known to both Rosemary and Melissa.'

A reward of $1million remains for any information leading to the discovery of Melissa's body or the conviction of her suspected murderer. 

A $200,000 reward exists for the identification or conviction of Rosemary's murderer.