Queensland police hope rewards will help find the killers of a young woman fatally stabbed on her way home, and a man who was shot and dumped in a river.

Hefty rewards are being offered in a bid to find the killers of two Queenslanders who died horrific and violent deaths.

It’s been more than a year since Shandee Blackburn, 23, was repeatedly stabbed as she walked home from work in Mackay.

Police are still hunting for the person who left her to die in the street on February 9 last year.

Officers are also still hunting for the killer of Julian Neuendorf, 38, whose bullet riddled body was found in the Logan River at Henderson Park on November 2, 2012.

Police Minister Jack Dempsey says a reward of $250,000 is available for each crime, for information that leads to a conviction.

“These murders were vicious and horrible acts and police have been working hard to track down those responsible, but so far each case remains unsolved,” Mr Dempsey said on Tuesday.

“Our hope is that by offering these rewards it will encourage people to come forward with the vital information detectives need.”

Ms Blackburn’s mother, Vicki Blackburn, recently spoke of her hope that someone would be held responsible for the horrific attack on her daughter, who died just metres from her home.

“I’m confident that the police will get there and the amount of time and effort and resources that they’ve put into it,” she told the ABC around the first anniversary of the crime.

The hunt for Mr Neuendorf’s killer has also stalled, despite a public plea for information by his sisters Anna and Emily.

Mr Neuendorf, a father-of-two who had a criminal history, suffered several gunshot wounds and his body was dumped at the end of the Logan Reserve boat ramp.