Call centre worker Andrew Gillen was last seen leaving his office in High Blantyre, Lanarkshire, last January.
The 42-year-old, from East Kilbride, has not been traced despite a nationwide appeal.
New searches are under way, with specialist officers and police divers.
Inspector Mark Leonard, who is leading the invest-igation, said: "I am appealing to the community of East Kilbride, particularly Andrew's colleagues or friends, to help us with additional information.
"Specialist officers, including police divers, will be conducting further searches around the wooded areas and open spaces in East Kilbride."
Officers have been searching for Mr Gillen since he went missing on Monday, January 7, 2013.
Inspector Leonard added: "An extensive search of the area where he was last seen and his home and surrounding area has been carried out.
"So far, unfortunately, there has been no trace of him. Initially there was a money trail established, however, this has since stopped."
Mr Gillen's worried family are desperate to know where he is and previously made a plea for help in finding him.
In a statement, they said: "We would like Andrew to know how much he is loved by all his family and that we are worried about him."
Mr Gillen is described as 6ft tall, with short brown hair.
He is clean shaven and wears glasses.
Inspector Leonard said: "Andrew lives alone and likes to keep himself. You might think that a year down the line your information may be of no use to us. However, I can assure you that any type of information you may have could be vital."
Anyone with information is asked to call 101.