Can you help solve this wedding ring mystery?

A DIVE operator is trying to reunite a former passenger from 20 years ago with a wedding ring, left behind on the Great Barrier Reef.

Sunlover Reef Cruises recently undertook a tidy up of its office at the Cairns Reef Fleet Terminal, where an envelope containing a wedding ring was found inside an envelope, inside a locked petty cash tin.

The gold ring has an inscription inside it, with the name "Marilyn" and a date, March 27, 1999 - assumed to be a wedding anniversary.

There is also the initials "AJL" engraved on the top of the ring.

Sunlover Reef Cruises is trying to unite a passenger from the with a long-lost ring that was found in an office clean-up. Sunlover Reef Cruises Group Marketing Manager Sarah Butler with the ring. PICTURE: STEWART MCLEAN

Sunlover spokeswoman Sarah Butler believed the ring had been found during a dive trip in January, 2001.

She said the piece of jewellery had remained as part of the company's lost property items at the company's old Trinity Wharf office during the early 2000s.

She said staff at the time had attempted to track down the owner, to no avail.

It was then shipped over to the new office during the move to the Reef Fleet Terminal a few years later, then forgotten about.

Sunlover Reef Cruises is trying to unite a passenger from the with a long lost ring that was found in an office clean up. PICTURE: STEWART MCLEAN

"I spoke to one of our original duty officers, who said they would have gone through the passenger manifest, but of course, there were no digital channels back then, and it was really hard to track people down," Ms Butler said.

"That's where the trail would have gone cold for her.

"But we're really hoping that the modern power of social media can help find the ring's owner."