Tony Parsons travelled from his home in Tillicoultry, Stirlingshire, on Friday, 29 September, 2017, to Fort William, intending to return home by bicycle and was reported missing on Monday, 2 October, 2017.
It follows the arrest of two men in December, however both were later released.
Mr Parsons travelled south on the A82 and was last seen around 11.30pm that night outside the Bridge of Orchy Hotel.
On Tuesday, 12 January, 2021, specialist search officers, supported by forensic scientists, discovered the remains in an area of ground close to a farm near the A82 at Bridge of Orchy.
Efforts to recover the remains will continue over the coming days before a post mortem is held to establish their identity.
The family of Mr Parsons have been made aware of the discovery and officers are in regular contact with them.
The inquiry is being led by detectives from Police Scotland’s Major Investigation Team, supporting local officers.
Detective Chief Inspector Alan Somerville said: “This is clearly a significant development and extensive work is ongoing to recover the remains and confirm their identity.
“We have informed Mr Parsons’ family, who are being supported by specialist officers. The thoughts of everyone involved in the investigation are with them at this difficult time.
“The investigation into Mr Parsons’ disappearance continues and I would like to take the opportunity to thank everyone who has assisted our enquiries so far and again urge anyone who may be able to help to come forward."
Anyone with information can to contact Police Scotland via 101, quoting reference 559 of 2 October 2017.
On Wednesday, 30 December, 2020, two men, both aged 29, were arrested and then released pending further enquiries in connection with the disappearance of Mr Parsons. Proceedings are now live under the Contempt of Court Act 1981.
Mr Parsons’ family have stated that they do not wish to make any public comment at this difficult time and have requested that their privacy is respected as they await further updates.