Sydney family pain in Missing Persons Week (AAP)

The heartache of not knowing is a pain the Joseph family shares with 1600 Australian families.

Their loved one, Raphael Joseph, has been missing since March, and police fear an extortion attempt was behind his disappearance.

The 37-year-old, once affiliated with crime gang DLASTHR - The Last Hour, was seen getting into the back of a late-model silver sedan in Auburn in western Sydney on the night of March 20.

He had spent time at his Chiswick apartment in Sydney's inner-west and at the Star casino in the hours before he disappeared.

After his family's frantic attempts to contact him, Mr Joseph was reported missing two days later.

Police have highlighted Mr Joseph's case to bring attention to the thousands of people reported missing each year.

Mr Joseph is among the 5635 people reported missing in NSW this year and of those 30 have not been seen for more than three months.

On average 35,000 people are reported missing in Australia every year and while 99.5 per cent are found, 1600 remain missing.

It is estimated for every missing person reported, at least 12 family members and associates are affected.

Detective superintendent Mick Willing of the Homicide Squad said it had been four months since anyone had seen or heard from Mr Joseph, also known as Rafi Tooma, Huss or Hussany.

"We believe he was kidnapped that night," he said on Sunday to mark the start of Missing Persons Week.

"We have spoken with many of his friends and associates, searched private properties, public spaces and bushland in hopes of finding clues."

Mr Joseph was extradited from the US to Australia over his suspected involvement in the fatal shooting of Dimitri Debaz in Sefton in 2002.

He appeared in court in Sydney in July 2008 charged with murder, but the case was later dropped.

He claimed an Australian crime family had a $100,000 bounty on his head payable to anyone who killed him.

Police are also using this year's national Missing Persons Week to raise awareness about people suffering from dementia as a key at-risk group.

http://au.news.yahoo.com/a/-/latest/24618159/sydney-family-pain-in-missing-persons-week/