Police offer $250,000 reward to solve Cooktown mum's murder

Queensland police have offered a $250,000 reward to help solve the murder of Cooktown woman Donna Steele.

The mother of two's body was found in August last year in the Endeavour River at Cooktown, in Cape York.

Police minister Mark Ryan announced today the reward for information leading to the conviction of those responsible for the "tragic" crime.

"We want to close this case," Mr Ryan told reporters.

"We want to provide closure to Donna's family. But we also want to make sure the person or people involved in this crime are held to account.

"That's why we have taken this extraordinary step of offering a reward."

Detective Inspector Damien Hansen said any possible accomplices, such as someone who helped dispose of clothing or weapons, could be granted immunity from prosecution if they came forward with vital information.

"It provides indemnity from prosecution for a person not involved in the actual offence," Det Insp Hansen said.

"As long as they are not the person who actually murdered Donna they are eligible."

The detective said he believed members of the Cooktown community had information and encouraged them to come forward.

Investigators have made multiple appeals for information and interviewed hundreds of people in their attempt to find Ms Steele's killer.

The last sighting of the 42-year-old was at the local IGA supermarket about noon on August 2, days before her body was found.