A reward is being offered in Australia and Germany to help solve the cold case murder of a German backpacker.

The death of Simone Strobel has baffled police in both countries for the past nine years.

The 25-year-old was last seen drinking in a Lismore pub on the NSW north coast on the 11th of February 2005.

Police said she then returned to her campsite at the Lismore Tourist Caravan Park.

Six days later her badly decomposed body was found in a sportsfield near the caravan park where she was staying.

Police were unable to work out how Simone Strobel died but did determine that she was not killed at the site where she was found.

Her boyfriend Tobias Suckfuell has been named by German prosecutors as the chief suspect.

The pair came to Australia on a 12 month working visa and planned to live and work around New South Wales.

The Bavarian office of criminal investigation is now offering a reward of 10,000 Euros to anyone in Australia or Germany with information that could lead to solving the crime.

Detective Inspector Matt Keogh from the Richmond command said police are relying on people who have information that have not yet spoken out.

He said there are specific questions that remain unanswered.

"Some things that we are looking at does somebody have information on the whereabouts of a pair of long white pants or a red skirt that belonged to Simone, we're also asking if somebody saw pieces of clothing at a later date in and around that area of the sportsfield or the Lismore Tourist Caravan Park," Inspector Keogh said.

"And any other people who were in the caravan park on the night (of Simone Strobel's disappearance) ... and heard anything or saw a supposedly drunk young woman and hasn't come forward to us."

Simone Strobel's death rocked the community of Lismore.

The Lismore mayor said people was devastated by the young woman's death.

"We were filled with shame that this could happen here, there were terrible feelings of grief for her family and the friends that she was travelling with," Councillor Jenny Dowell said.

"There was an outpouring of grief and the wall of the club near where she was found was covered in flowers and candles and there was virtually a vigil there for days."

Councillor Dowell has had close contact with Simone Strobel's family in the years since the woman's death.

"They were overwhelmed by the response from the people of Lismore, both the fundraising that took place (and the memorial site)," Councillor Dowell said.

"Opposite the site there is a granite seat with an engraving at the end of the seat with a favourite quotation of Simone's and there's a tree."

The Strobel family also made a donation in their daughter's name to the Lismore children's charity 'Our Kids'.

Jenny Dowell said the Strobel family are in everyone's thoughts today and pleaded with anyone in the Lismore community with information to come forward.

"We need a solution to this, we need the answers," she said.