A nurse passed out at HMP Edinburgh after inhaling drug fumes while helping an inmate.

It is understood she inhaled second-hand smoke from the drug Spice after a cell door was opened in the jail's Hermiston wing.

The Scottish Prison Service (SPS) said it takes the issue of substance misuse very seriously.

But the Royal College of Nursing (RCN) described the circumstances as "completely unacceptable".

RCN Scotland director Theresa Fyffe added: "It's a major concern that nurses, who are trying to treat and care for people who are sick or injured, are having their own health affected.

"There needs to be clear policies in place to make sure all staff are kept safe from harm in their working environment and the Scottish Prison Service must take steps to ensure this cannot happen again."

An SPS spokeswoman said: "A comprehensive range of robust security measures are in place to prevent the introduction of contraband into our prisons.

"Significant investment continues to be made in the development of new technology and staff training to detect, deter and reduce the availability and supply of illegal drugs.

"Anyone found in possession of contraband is reported to the appropriate authorities.

"SPS recognise that substance misuse is prevalent amongst those entering our care and as such a range of substance misuse treatment and support services are offered to all those entering our care."