Graffiti in a laneway behind an outback pub could be the key to solving a cold case investigation into the suspected murder of a tradie who disappeared more than a decade ago.
Charlie Park, 66, was last seen entering his home in Kalgoorlie-Boulder in Western Australia's Goldfields region after a night at a bar with a colleague on January 3, 2012.
Despite several public appeals for information, detectives have been unable to unearth how and why Mr Park disappeared, but it is believed he could be the victim of foul play.
"Charlie Park was on some prescribed medication and hasn't taken that medication in quite some time from when he was reported missing," Detective Senior Sergeant Uwais Cuff told reporters on Tuesday.
"His bank accounts haven't been accessed, and he hasn't used his mobile phone since he's reported missing, so we're treating that as suspicious."
Graffiti daubed in gold-coloured paint on a fence behind the Recreation Hotel in Boulder could be linked to Mr Park's disappearance, Mr Cuff said.
It was painted in the month before Mr Park went missing and appears to say "Charles Athostan Park", although words have been blurred in photographs supplied to the media by the police.
Investigators say the message targeted Mr Park and a blurred word was a "horrible allegation".
"There's been absolutely no information or anything to suggest that there was any truth behind it at all, so we've chosen to blur that word," Mr Cuff said.
Cold case detectives have this week travelled to Boulder to speak to locals in the hope of finding new clues that could help the investigation.
"Incidents like this in small, tight-knit communities like Boulder and Kalgoorlie, it really has a long-term impact and effect," Mr Cuff said.
"Someone out there knows something which could be the vital piece of information we need to solve this."
A $1 million reward has been offered for information that leads to the arrest and conviction of the person or persons responsible for Mr Park's death.
Gold mining town Kalgoorlie-Boulder, commonly known as just Kalgoorlie, is a city in the Goldfields-Esperance region of WA, about 595 km east-northeast of Perth.
