Ontario's ministry of the solicitor general is investigating a string of suspected overdoses at the Maplehurst Correctional Complex in Milton, Ont. that has left one inmate dead.

One inmate is still recovering in hospital. Four other inmates who were treated in hospital have been taken back to the provincial jail.

"We are focusing on whether policies and procedures were followed and the investigation is underway," ministry spokesperson Andrew Morrison told CBC Toronto on Wednesday.

Six male inmates in all were taken to the hospital by paramedics for assessment on Tuesday evening after police and paramedics received a call at 5:50 p.m.

Multiple investigations now underway

Staff at the jail performed first aid and called emergency crews, Morrison said. Police were told that several inmates were in medical distress and required medical attention.

The inmate who died was pronounced dead in hospital, he added. Police have not released his name and age. They have also not disclosed the condition of the inmate still in hospital.

Morrison said a number of investigations are now underway. When a death occurs involving an inmate in provincial custody, the ministry, police and the province's coroner all investigate, he said.

A view of the Maplehurst Correctional Complex in Milton, Ont. Andrew Morrison, spokesperson for the ministry of the solicitor general, said in a statement: 'Crime, violence, mental health and addictions are complex issues that cannot be solved overnight or by the provincial government alone.' (Google Maps)

The ministry looks at policies and procedures in terms of care of the inmate who died. The police look at whether there was any criminality involved. The coroner determines cause and manner of death.

If the coroner decides that the death was not due to natural causes, the government would call a mandatory inquest to examine the circumstances.

"Crime, violence, mental health and addictions are complex issues that cannot be solved overnight or by the provincial government alone," Morrison said in a statement on Wednesday.

"The government is committed to working with its partners across Ontario to keep our communities safe."

'There are a lot of moving parts here'

Const. Steve Elms, spokesperson for the Halton Regional Police Service, said officers were at the jail on Wednesday to gather evidence.

"The investigation is still unfolding and information is coming in fairly fluidly here," Elms said. "There are a lot of moving parts here."

Halton Regional Police received a call about the suspected overdoses at 5:50 p.m. on Tuesday. Officers were at the jail on Wednesday to collect evidence. (Halton Regional police)

On Monday night, police said all of the inmates involved had been confined to the same cell block and that an illegal drug was involved.

Police have not determined how the drug made its way into the jail and have not said what type of drug was used or how.

Union wants naloxone kits for front-line guards

Chris Jackel, chair of the Ontario Public Service Employees Union's Ontario corrections division, said the suspected overdoses occurred all at the same time and in one area at Maplehurst.

"Late in the afternoon, at about 5 o'clock, these inmates began to show signs of overdose and they really just starting dropping, one after another. Staff responded to the incident. Their work was impeccable," he said.

Jackel said he could not release further details because the incident involved a death. OPSEU represents 5,000 correctional officers and 4,000 correctional members.

Though the ministry has yet to confirm that the overdoses occurred, Jackel said the union would like to see naloxone kits issued to all front-line officers. Each unit office in a jail might have a kit, he added.

The union representing correctional officers wants more naloxone kits in jails. (Sarah MacMillan/CBC)

"We have naloxone kits in our jails but they are only in limited amounts," he said. "If we were all issued our own naloxone kits, it would be a time-saving measure."

Illegal drugs, sometimes in liquid form, are believed to be coming into jails through the mail and on inmates themselves. The union wants the ministry's dog handling unit expanded, the number of ion scanners in jails increased to detect traces of drugs and addiction services made more available in jails.

"This really reflects the opioid crisis that is occurring in our communities. Correctional institutions, by default, become a bit of a microcosm of society at large. When we see these things in society, they usually trickle in to our institutions," Jackel said.