The number of Drug Treatment and Testing Orders (DTTOs) imposed by the courts has reached its highest level in Scotland for five years - but less than two-fifths are successfully completed.

While 55.5% of DTTOs - which are an alternative to prison for offenders who are addicted to drugs - were successfully completed in 2014-15, this had fallen to 37.3% by 2018-19 - the lowest completion rate for seven years.

At the same time the latest criminal justice social work statistics, released by the Scottish Government, show the number of such orders handed down by the courts increased from 475 in 2016-17 to 595 in 2018-19.

The figures also show the number of people who avoided prosecution, sometimes on the condition they complete a social work scheme, rose by 7% last year, according to the data.

There were 1,849 cases "diverted from prosecution" in 2018-19, up from 1,725 the previous year.

These are less serious cases when the procurator fiscal decides "prosecution may be waived or a decision on prosecution deferred pending successful completion of the social work scheme", in the hope that this will deter the person from further offending.

READ MORE: Thug attacked police officer at Glasgow Diamond Dolls strip club

The number of community payback orders (CPOs) imposed by the courts was down by 8% last year, from 17,877 in 2017-18 to 16,418 in 2018-19.

The orders were introduced by the Scottish Government in 2011, with offenders having to comply with up to nine different conditions, such as completing unpaid work, paying compensation to their victim or being supervised by a social worker.

Last year, less than three-quarters (73.4%) of CPOs included a requirement for the offender to do unpaid work, down from 78.3% in 2014-15.

The average number of hours of unpaid work criminals are required to do has risen over the last four years, however, to 127 hours in 2018-19.

READ MORE: Man stabbed 'multiple times' in Paisley by knife-wielding gang in shock attack

In more than half (52%) of the orders with a requirement for unpaid work in 2018-19, the total imposed was more than 100 hours.

Around eight million hours of unpaid work has been carried out by offenders on community sentences since 2011, the Scottish Government said.

Justice Secretary Humza Yousaf said: "While prison is necessary for offenders who pose a significant public safety risk, short-term custodial sentences are an ineffective means of rehabilitation.

"Imprisonment, including remand, disrupts families and communities, employment and housing - the very factors that deter offending and keep crime down.

"Unpaid work completed by people serving CPOs benefits local projects and helps them to become active and responsible contributors to their community."

He added: "We recognise that some individuals will require sustained support and we are investing £9.5 million a year more in community justice services compared to 2015-16 as part of more than £100 million funding for justice social work.

"Many people in the justice system have chaotic backgrounds and struggle with addiction and mental health problems - issues that won't be solved by a short period in prison, where hard-working staff should be focused on the most serious offenders.

"Community sentences, with supervision and other conditions where necessary, add structure and help people make the positive changes needed to tackle the causes of their behaviour."

READ MORE: Glasgow shop sells 2000 'don't die, please buy' coronavirus face masks

Scottish Conservative justice spokesman Liam Kerr said the Scottish Government's approach was not working.

"The SNP's soft touch justice clearly isn't an effective answer to Scotland's rising crime rate," he said.

"This significant increase in diversions from prosecution denies more victims the justice they deserve while offenders avoid any meaningful punishment.

"While early and positive intervention by social work could be helpful, there is a danger that young offenders are simply being recycled back onto our streets."

Mr Kerr added: "In addition, many of the payback orders that are being completed aren't starting on time, and many aren't rehabilitating the criminals who do finish them.

"Crime has risen for two years in a row and violent crime rose by 10% last year alone."