POLICE have closed the investigation into the death of South Gladstone man Michael Ceremuga, concluding there are no signs anyone else was involved in his death.
Mr Ceremuga's body was found deep inside a storm water drain underneath Gladstone Benaraby Rd at Toolooa on May 25 this year.
The decision to close the investigation came after the toxicology report from an autopsy performed on his body failed to provide any conclusive evidence as to how he may have died.
Detective Senior Sergeant Tony Andersen said the death had been ruled non-suspicious and the matter was now in the hands of the state coroner.
"The coroner will review the file, review everything we've put to them, and make any decisions from there," Snr Sgt Andersen said.
His father, Stan Ceremuga said the decision to close the investigation without a cause of death would do little to bring closure to his family.
"We are still just looking for the answer to what happened," he said.
"It was a shock for us.
"It is for me very hard to believe that Michael crawled to the place where he was found... I just cannot imagine Michael doing so.
"I have decided to wait for (the) coroner's report, because the coroner could ask police for some more investigation."
Mr Ceremuga said his son had been a known drug user, but had taken steps before his death to stay off drugs.
"In February (he visited) Thailand, and in Thailand he was scared of their police's approach to drugs," he said.
"After that he went for a trip to Japan. His approach was changing - he liked something other than drugs."
He said despite the investigation closing, the family was appealing for the public to come forward to The Observer with any information that could help.
"Maybe someone's seen something, maybe he was meeting some people in that area," he said.
Update your news preferences and get the latest news delivered to your inbox.