More than five months after the mysterious disappearance of Theo Hayez, a disturbing object has surfaced, fuelling speculation over the 18-year-old Belgian backpacker's possible fate.

A wooden club, about 1.5 metres long, was handed in to police about three weeks after Hayez was reported missing, stained with what appears to be blood and with the words 'The Judge' inscribed.

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The bludgeoning object, wrapped in duct tape at the handle end, was posted on Facebook by Jenny Bannister earlier this week.

“Found in Clarke’s Beach dunes camp site … 3 weeks after Theo disappeared.

“Handed into police at the time.

“Stains on bludgeon stick (looks like blood).

“The writing on bludgeon stick says: THE JUDGE.

“Never heard back?”

The Facebook post showing the found club. Credit: Jenny Bannister / Facebook

7NEWS.com.au is seeking comment from Byron Bay and Tweed Police, who took possession of the club after it was handed in.

Hayez was last seen on May 31, leaving the Cheeky Monkeys nightclub.

His belongings were found in his hostel room on June 6, and it was then he was reported missing.

Theo Hayez, 18, who vanished after leaving the Cheeky Monkey's bar in Byron Bay in NSW, about 11pm on Friday, May 31, 2019. Credit: TWEED BYRON POLICE DISTRICT / AAP

Despite weeks of extensive searches - by land, air and sea - involving hundreds of volunteers and authorities, Hayez has not been found.

In July, a Puma branded baseball cap was found close to where the last "ping" from the backpacker's mobile phone was recorded.

It was sent away for DNA testing but police say the results were inconclusive.

SES volunteers search for missing Belgian backpacker Theo Hayez around Watergos beach, Byron Bay, in June. Credit: REGI VARGHESE / AAP

On September 18, the search was officially called off and the case referred to the NSW coroner.

The Hayez family said their resolve to find their son was not weakening, and they hoped the handing of the case to the coroner may mean more investigative resources were directed to the matter.

Laurent Hayez, father of missing Belgian backpacker Theo Hayez, and two Hayez family members launch a public appeal for information on June 17. Credit: AAP

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