Canberrans and friends of missing 39-year-old Stuart Heddle are coordinating a poster campaign to help locate the man who has been missing since Saturday morning.
He left his wallet and mobile phone at home and police and his family are gravely concerned for his safety.
A Facebook page has been created for concerned Canberrans to share information, coordinate search activities, and download missing person posters for distribution across the ACT region.
The posters are now being placed in post offices, supermarkets and bus stations in Canberra's southern suburbs to towns as far away as as Bemboka on the south coast.
One user, who met Mr Heddle through her daughter's involvement in the Tuggeranong Vikings Water Polo Club, said the kids at the club "all love Stu and are devastated by his disappearance".
"The fact that strangers are motivated to help is fantastic," she said.
"A husband, dad, and friend is missing and we want him to be safe and home as soon as possible.
"People are putting flyers out all over Canberra, using social media connections, contacting businesses, and in the background supporting Jenny, Jordy and Aidan."
The missing person posters have also been circulated via the internal emails of a number of public service departments in Canberra.
"Stuart, I love you. Your beautiful children Jordan and Aidan are desperate to see you or know you are OK," she said.
"You and I have been together forever. You are my best friend, my soul mate, and the greatest dad ever."
While sitting beside Mr Heddle's brother Ian and fighting back tears, she called on her husband to "hang on until we can find you".
"Your children, Ian, your parents and extended family and friends are all wanting you to come home," she said.
Police have increased search efforts in Tuggeranong, with SES volunteers assigned to bushland adjacent to the Monaro Highway and water police patrolling waterways in the area.
An initial search has been conducted in the area of Mr Heddle's home in Chisholm but police are now relying on public information to target their efforts.
Detective senior constable Paul Reynolds said Mr Heddle did not take his mobile phone or his wallet with him when he left on Saturday.
"This is very out of character for Stuart, and his family are tremendously concerned for his welfare," he said.
"The family has said that Stuart is a generous person, fastidious in maintaining his appointments, is very caring, he loves his family, he loves his friends, and this is very out of the ordinary.
Mr Reynolds said there was nothing to suggest "foul play" in Mr Heddle's disappearance and their priority was to locate him as soon as possible.
"Stuart is not in any trouble at all. We are concerned for his welfare," he said.
"Stuart, if you do choose to present yourself at a police station or to call us, we just want to make sure you're all right and you're not in any trouble."
Anyone with information should phone the police on 131 444.