Three people have died at a Dorset prison in two years after taking the illegal drug Spice.

Government inspectors found HMP Guys Marsh had a “serious drug problem” when they visited the prison in December last year.

In the space of six months more than 200 inmates needed medical treatment for overdosing on the psychoactive substance, according to a report published recently.

In March it was revealed

criminals had stuffed dead rats with drugs and mobile phones in an attempt to smuggle the contraband into the prison

.

Inspectors said a “wide range of security measures had been taken to cut the supply of drugs” since their last inspection in 2016, but “more work was needed”.

“There had been many incidents, and sadly some deaths, relating to the use of illicit drugs, and to the issues of debt and intimidation arising from the trade in those drugs,” the report said.

Levels of violence at the category C prison near Shaftesbury were “higher than in similar prisons”, inspectors found, and “driven by drug use and debt”. There were 148 assaults in six months, 45 of which were against staff. Twelve per cent of assaults had been serious, “which was a concern”.

As well as the three drugs-related deaths, one person had died by suicide and another inmate had died of natural causes since 2016.

“The cluster of deaths in summer 2018 had led to a renewed focus on suicide prevention, and on the clear link between self-harm, the use of new psychoactive substances and associated debt,” inspectors said.

Peter Clarke, HM Chief Inspector of Prisons, said while there were still concerns about safety at Guys Marsh, it had changed from being an “out of control” prison in 2014 to a “calmer, more settled institution”.

“This inspection of Guys Marsh evidenced tangible progress for the first time in many years. There was still much to correct and improve but managers were visible and there was good leadership, as well as commitment and enthusiasm among those who worked there,” he said.