Eight people were arrested on Wednesday morning during simultaneous raids the Middle Eastern Organised Crime Squad rolled out across Sydney's west.

Among those in custody is a 29-year-old woman, accused of running a drug syndicate, which included teenage boys as its members, in the greater Fairfield area.

Police allege she was closely associated with Oliver Merza, a familiar name in the Assyrian organised crime milieu.

It has been alleged Mr Merza has links to the gang DLASTHR but his family say that the group does not operate any more.

"That hasn't existed since the '90s," Mr Merza's sister, Oleen, told Fairfax Media while police searched her parents' home in Fairfield Heights on Wednesday.

"The members are all doing time in jail or they are out in their 40s, married and with kids. They [police] keep associating these kids with groups like that.

"Our family got here in 1995 and the group died out in 1998.

"We were in primary school when the group separated."

She said that Mr Merza, the oldest brother in her large family, and his siblings came from a good family - of psychologists, teachers and a financial adviser - and they had been deeply embarrassed by the police attention.

Mr Merza is in custody awaiting trial after officers allegedly found guns at a house he was at, and charged him over the stabbing of a 14-year-old last year.

Oleen said Mr Merza, who had a lawnmowing business, had been accused of acts he didn't do.

"Ollie is frustrated," she said.

"If he got caught for something he had done, he would have pleaded guilty as he has done before. But he has no idea why he is in there."

Wednesday's operation comes after ongoing tit-for-tat violence, including shootings, stand-over tactics and firebombings, allegedly linked to an ongoing feud between Assyrian organised crime groups.

While investigating those crimes, Strike Force Barcom uncovered links to the supply of cannabis in the area.

The 29-year-old woman was at her Cabramatta home alone when police stormed in and arrested her just before 7am on Wednesday.

Officers are searching her single-level brick property and bagging evidence.

She has been taken to Cabramatta police station to be questioned.

Other raids in Fairfield and Elizabeth Hills targeted younger members of the group, including two 17-year-old boys and a 15-year-old, all of whom have been arrested.

Eight people have been taken to various police stations and are expected to be charged with drug and criminal group offences.

One of those targeted includes the brother of an alleged associate of the DLASTHR, who is in jail.

Detectives revealed last month that Assyrian gang associates may have been involved in the fatal shooting of ex-bikie Adrian Buxton.

Mr Buxton, a former member of the Nomads, was killed outside his home in Colyton on May 19, 2016.

Police believe one of the gang figures' cars - an Audi Q7 - was used in the shooting.

That car was later handed to Antonio Hermiz, who was shot dead in Wetherill Park in December.