New reward to find Queensland woman Deborah Smykalla's killer

Police have renewed their search for the killer of Queensland woman Deborah Smykalla, who was found strangled to death in her home with a dog lead more than 40 years ago.

A new $500,000 reward has been offered for anyone with information that may lead police to the 22-year-old's killer.

Smykalla was found dead in her Redlands home around 9.45pm on September 6, 1981.

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She was found on the kitchen floor with a dog lead wound around her neck as a small fire burned in the room.

"There was a small fire in the kitchen that was smouldering on police arrival and an overturned heater on the carpet," a statement read.

"Police believe an unknown person attempted to set the house alight."

Smykalla lived at the Capalaba house with several housemates and three dogs.

On the day of her murder, Smykalla was seen in her yard with a man in his 20s who was described as thin with short brown hair.

"Later at approximately 7.30pm, two people were observed to be sitting on the front porch," police said.

"Detectives would like to speak with these people or anyone with information about their identities."

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A motorbike, possibly a 250cc or 500cc road trial bike, was also seen at the address.

In 2014, more than 30 years on, police received an anonymous tip including specific details about who was responsible for Smykalla's murder.

Detectives are urging whoever made the Crime Stoppers submission to come forward once more to assist with enquiries.

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Detective Senior Sergeant Tara Kentwell said she hopes the $500,000 reward will be key to finding those responsible.

"Police have commenced a full review and know there are people out there who can provide crucial information in regards Deborah's activities and movements around the time of her death," Kentwell said.

"The smallest piece of information could lead to a breakthrough in the investigation and I encourage anyone who has information about who was responsible for Deborah's murder to come forward".

The reward includes an opportunity for indemnity against prosecution for anyone involved who did not commit the murder.

New forensic technology will also be used to analyse any DNA left on the dog lead found around the young woman's neck, with testing underway at the Institute of Environmental Science and research in New Zealand.

Smykalla's sister Diana Walton described her as loving and kind, entering a new phase of life as a young woman in her 20s.

"She was very free-spirited, fun-loving, she loved animals ... and she'd often bring home lame animals that she found by the side of the road, she had a beautiful heart," Walton said.

"Her murderer has been free to walk free while her life was cut short at their hands.

"We would like justice for her and closure for us.

"It won't bring her back, that's true, but there's someone out there who knows something."