Darren, whose surname was not provided by officers, was last seen in Abingdon at around 4.30pm on Saturday, March 9 before being reported missing to Thames Valley Police later that day.
Police launched an urgent search for him before confirming they had found a body, believed to be Darren, in Tilsley Park on Sunday morning, March 10.
Tilsley Park, on Dunmore Road, has woodlands and sports playing fields and is less than two miles from the Abingdon town centre.
A police spokesperson said: “Sadly, the body of a man was located yesterday morning.
“Although formal identification has not yet taken place, we believe this to be Darren.
“Darren’s next of kin have been made aware and are thoughts are with them at this extremely difficult time.
“The death is being treated as unexplained but not suspicious, and a file will be prepared for the coroner.
“We’d like to thank everyone who helped with our search and who shared our appeal.”