Ricky Ciano, 35, who was president of the Rebels outlaw motorcycle gang's Sydney chapter before he left the club in 2015, hasn't been heard from since he spoke to his wife on Saturday night.

Mr Ciano left the bikie fraternity behind to move to the Gold Coast, where most of his family live, for a lifestyle change, friends say.

He travelled to Sydney on the weekend to visit his daughter but hasn't been seen since.

Friends and family have been searching frantically for the father-of-five and fear something untoward has happened to him.

Mr Ciano was the target of an alleged failed murder attempt at his Central Coast home in 2015.

Former Rebels Burwood chapter member Abuzar Sultani was allegedly offered $500,000 to kill Mr Ciano and conspired to carry out the contract through a staged pizza delivery.

However, the alleged execution attempt was thwarted when Mr Ciano refused to open his Wamberal home.

Mr Sultani has been in custody since November, charged with conspiring to murder Mr Ciano, along with the alleged murder of crime figure Pasquale Barbaro.

A close friend, who spoke on the basis of anonymity, said Mr Ciano was in the Penrith area on Saturday and made it to a friend's house that night.

The friend said he sent his wife a few text messages, including one saying there was a blackout and he couldn't charge his phone.

He hasn't been heard from since last speaking to his wife at 8.20pm and never made it to visit his daughter.

"It is completely unusual because he was down to visit his daughter and his daughter is his life so he wouldn't miss it," the friend said on Tuesday.

"It is completely out of character for him not to contact friends or family for three days."

He hoped people who sighted the tattooed 35-year-old over the weekend could help piece together his last movements.

"Of course there are concerns about an ex-bikie leaving a club, from what is reported in the media, that is why we are worried."

Police searched Mr Ciano's Hornsby unit on Tuesday but found nothing untoward.

Fairfax Media has previously reported on the conditions that come with leaving a bikie club, including handing back one's bike or paying a hefty fee.

It is understood Mr Ciano was told he could walk away from the club under certain conditions, including that he remove his club tattoos.

With no sign of him for the past three days, family and friends are desperate to hear from anyone who has spotted Mr Ciano.

"He was in a good frame of mind, happy to be around friends so this is out of character," his friend said.

Anyone with information can contact Crime Stoppers on 1800 333 000.