Employees who worked at an injection facility have been arrested for their alleged role in a heroin trafficking ring.

A 36-year-old woman and a 49-year-old man were arrested outside the injection centre on Lennox Street in North Richmond, Melbourne on Thursday.

The Brunswick west woman and the Richmond man provided advice on harm reduction to drug users as part of their job.

At least six others, who were not staff members, were also arrested for alleged drug trafficking and were regular users of the injecting room, 7News reported.

At least eight people were arrested (one pictured) accused of drug trafficking, which included two social two employees who worked at an injection facility

Victoria Police said the alleged drug dealing did not take place at the injection facility.

The social workers have been stood down, the North Richmond Community Health Centre who overseas the operation of injection rooms confirmed.

Acting Mental Health Minister Luke Donnellan said: 'Such alleged behaviour is completely unacceptable and will not be tolerated.'

'The Government will swiftly investigate this matter and take action.'

Detectives carried out raids across multiple properties in Richmond, which saw eight arrests in total.

Drugs and cash were subsequently seized by police.

Police officers at the injection facility on Lennox Street (pictured), where they arrested a 36-year-old woman and a 49-year-old man

At least six others were also arrested for alleged drug trafficking and were regular users of the injecting room (pictured)

The other six who were arrested included a woman, 43, and a man, 51, both from Burnside Heights and were arrested in Gardner Street, Richmond.

A man and a woman, both 42, were arrested in Egan street, while a 35-year-old man was apprehended in Murphy Street.

A 40-year-old man was also arrested in Elizabeth Street.

The arrests are part of Operation Sievers - a three month investigation into drug trafficking.

Acting Superintendent Kelvin Gale said: 'While we recognise those who use illicit drugs have a health problem, we also know that drugs are a big contributor to crime in Victoria.'