Greg Armstrong was 30 years old when he was last seen on May 7, 1997, and was living in Maryborough. His landlord reported him missing.

Recent information received prompted searches of bushland in the Tuan State Forest, south of Maryborough.

Police said the investigations would remain ongoing and continue until all opportunities to advance the investigation had been exhausted.

Further to the $250,000 reward, any accomplice to the suspected murder would be given indemnity against prosecution.