NEARLY two out of three councils in Scotland have a shortage of mental health officers, according to new research.

Local authorities said the specialist social workers who advocate for those at risk of detention because they are a risk to themselves or others, are clocking up hundreds of hours of extra work.

The Liberal Democrats believe shortfalls could threaten the rights of those whose liberty is taken away because of concerns about their mental health.

The party, citing 2013 figures published in the days after last year's independence referendum, said there were only 674 mental health officers (MHOs) north of the Border.

That is the same number recorded in 2008, the first full year of SNP power, despite the subsequent rise in population.

It also marks a decrease from 698 at the end of 2012, although more MHOs are now full-time and specialist.

LibDems health spokesman Jim Hume said: "I'm concerned that the rights of people with mental ill health will increasingly be at risk unless the Scottish Government takes immediate action to support MHOs.

"The number of Mental Health Officers per 100,000 population is now at the lowest since the SNP came into power. The number of MHOs has fallen to 674 at a time when the population is growing.

"MHOs provide an important safeguard of ensuring that all options are investigated before using compulsory admission of an individual with mental ill health. They are a vital link in protecting an individual's rights, properties and possessions.

"It's unacceptable that SNP ministers should allow the number of MHO's to fall further at a time when, in some areas, nearly six out of ten of emergency detention certificates have been achieved without MHO consent.

MHOs advise individuals of their rights, including their right to independent advocacy and legal representation.

They also provide consent for people to be assessed or treated in hospital on an emergency or short-term detention certificate.