Two outreach workers tasked with directing people to the North Richmond centre are among eight people arrested by police during the latest illegal drugs crackdown in the area.

The arrests have put pressure on the already-controversial facility a few months from the end of its 18-month trial.

"People come here because they don't want to die," a worker from inside the centre - not involved in the raids - told AAP on Friday.

Wanting to speak anonymously in support of the centre's work, they said the facility is fitted with numerous security cameras and patrolled by guards, making wrongdoing inside or nearby impossible.

"This is a safe place ... used by people of all ages, genders and races," a second worker told AAP.

Police do not allege any drug trafficking occurred within the centre.

Michael Tran, 35, was the first of those arrested to have a matter mentioned in court on Friday.

Tran did not face Melbourne Magistrates Court, but charges of trafficking heroin and conspiracy to traffic heroin were confirmed against the Richmond resident.

The magistrate refused to release details of the criminal charges.

A 49-year-old Richmond man has been charged with drug trafficking and a 36-year-old Brunswick West woman is due to be charged on summons with the same offence.

The pair worked as outreach workers, employed by North Richmond Community Health.

Three other people, a man and two women, have also been charged with trafficking drugs, believed to be heroin.

Two other people were arrested on Thursday but released without charge.

The arrests have drawn further criticism of the centre, which has previously been slammed for its location close to a primary school.

"You have to call into question the current management of the site," neighbourhood spokesman Dave Horseman told Network Ten.

The state government has stood aside North Richmond Community Health CEO Demos Krouskos and announced an urgent inquiry into the matter.

The health service operator recently completed an audit of the staff it employed and no convictions were identified, government MP Luke Donnellan said.

Opposition Leader Michael O'Brien said Mr Krouskos was being used as a scapegoat and called for the centre to be separated from a co-located needle exchange centre and maternal health centre, and further away from the school.

But there is bipartisan support for the injecting room trial to continue. It opened in June 2018 for an 18-month trial and has recorded more than 60,000 visits and managed more than 1800 overdoses without a death.

A review of the trial is due in June 2020 to help decide of it will continue to operate.

Tran along with four co-accused are due in Melbourne magistrates Court on Tuesday.

Australian Associated Press