A 51-year-old man has been charged in connection with historical sexual assault allegations in following a DNA breakthrough.

The man was arrested in Panania, in Sydney's south-west, about 6am today and taken to Bankstown Police Station.

He has since been charged with four sexual assault offences, following the reopening of the case in 2020.

A man, dubbed the "Inner West Rapist", was accused of 13 separate sexual assault offences against women between August 23, 2003 and November 2, 2004.

Then earlier this year, experts from NSW Health Pathology's Forensic and Analytical Science Service (FASS) revealed they had established a familial DNA link in the case.

A DNA match was identified with help from the Forensic Evidence and Technical Services Command's DNA Management Unit.

Child Abuse and Sex Crimes Squad Commander Detective Superintendent Jayne Doherty said many of the assaults happened in the homes of the survivors of sexual assault or nearby.

Detective Superintendent Doherty said the man's DNA profile will be checked against existing police databases to determine whether he has any links to the remaining nine crimes.

"We're conducting further inquiries. It's very early in the piece after the arrest," she said.

"Any offence that takes a woman in her own home is horrendous.

"This person was dubbed the Inner West Rapist and there were women who were terrified in their own home.

"The impact on those people and the community as a whole cannot be underestimated."

Strike Force McCoy was established in March 2004 but despite assistance from the Federal Bureau of Investigations (FBI), local detectives exhausted all leads involving more than 3000 persons of interest.

Detectives from the State Crime Command's Child Abuse and Sex Crimes Squad completed a forensic review when they reinvestigated the case in February 2020.