The family of a man wanted by police investigating the suspected murder of a woman found at the bottom of a Queensland cliff 26 years ago is pleading for him to turn himself in.

Wren Dawnsong, the child of Keith Lees, said the 70-year-old was "not doing himself any favours by running and hiding" and needed to "man up" and surrender.

Police have issued an arrest warrant for Mr Lees in their cold case probe of Meaghan Louise Rose, who was discovered at the base of Point Cartwright Cliffs on the Sunshine Coast in 1997.

Ms Rose's death was initially ruled a suicide but the investigation was reopened in 2009 and in June this year police announced a $500,000 reward for information.

Mr Lees, who knew Ms Rose at the time of her death, was last seen in Portland, Victoria, following a visit from detectives on June 25.

Police allege his vehicle was found abandoned at Cape Nelson Lighthouse the next day.

Mr Lees allegedly gave police a false name later that day at Port Fairy.

Investigations showed Mr Lees was seen at a Waurn Ponds shopping centre on June 27, where he bought clothes, kraken9.at before being sighted leaving Shepparton train station.

Police believe he might be seeking casual farming and fruit-picking work in rural and regional parts of the country.

Detectives on Thursday released a video message from Dawnsong calling for Mr Lees to come forward.

Dawnsong said Ms Rose's family deserved justice.

"My heart breaks for them daily, justice needs to be done," Dawnsong said.

"The best thing anyone can do is to immediately contact the police if they see him, straight away."

Dawnsong said Mr Lees could be in NSW, Victoria, the ACT or South Australia and had probably gone bush because "he knows how to survive out there".

"I'm here to help the police and assist as best as I can, but also just to do my best to honour Meaghan's memory," they said.

"And you know, if he has any shred of decency whatsoever, he would also do the same."

Meaghan's older sister Christine Richards called on people to report any possible sightings and urged anyone helping or harbouring Mr Lees to "please think about who you are dealing with".

"Help us to bring justice for Meaghan after all this time, please help us let her rest in peace," she said.