Cops reopen Sydney's 1974 pantyhose murder

Julia Carlisle

The brother of a young teacher found raped and strangled in her Sydney home more than 45 years ago will join authorities in appealing for information to catch her killer.

The body of Maria Smith, 20, was reportedly found by her husband in the bedroom of their Randwick unit on April 22, 1974. She had been bound, sexually assaulted and strangled with pantyhose, police said.

Despite extensive investigations over the years, no one was charged with her murder and the state government will offer a reward on Tuesday.

It comes as NSW Police announced on Monday about 500 cold case homicides dating back four decades would be reopened and re-examined with fresh eyes and cutting-edge technology as police attempt to catch the killers.

Squad commander Detective Superintendent Scott Cook says specialist detectives from across the force will conduct formal case reviews.

"While the unsolved homicide unit is a finite resource, the NSW Police Force has a wealth of investigators whose skills can be harnessed to increase our capacity to put fresh eyes on cold cases," Det Supt Cook said in a statement on Monday.

The request for "fresh eyes" to examine the cases came from victims' families, police said.

Ms Smith's brother Peter McGuinn will join Det Supt Cook along with NSW Police Minister Troy Grant on Tuesday to announce a new reward for information that leads to a conviction.