Scotland has a disproportionately high share of the UK�s human trafficking victims yet no-one has been prosecuted north of the border, according to a new report by Amnesty International.

Scotland has a disproportionately high share of the UK's human trafficking victims yet no-one has been prosecuted north of the border, according to a new report by Amnesty International.

The study highlights grave concerns about the lack of suitable accommodation and support for victims and problems in correctly identifying them.

In some cases the report, which will be launched on Wednesday, reveals help could have been offered earlier to potential victims but authorities failed to act.

Two of the Chinese cockle-pickers arrested after the Morecambe Bay tragedy in 2004, in which 23 people died, were detained and released in Scotland the previous year for the same activity, the study reveals.

It also found that some of the women and children trafficked into Scotland for sexual exploitation and domestic slavery were subsequently sent to Dungavel detention centre, rather than being treated as victims.

Of those who were found accommodation, many simply disappeared, raising concerns they may have been stolen back by their exploiters.

The report also highlights concerns that Stranraer is being used as a trafficking route.

The researchers were told that in January 2006, a 15-year-old girl was discovered by police carrying £5000 in cash. She had arrived from Belfast. Although she was passed on to social services, she is since thought to have disappeared.

In 2006, during Operation Pentameter 1, police forces in Scotland visited 25 premises, made 12 arrests and uncovered 10 women, five of whom were confirmed as trafficking victims. During Operation Pentameter 2, which ran from late last year until early this year, more than 50 premises were visited in Scotland, 59 people were dealt with as victims of trafficking, of whom 15 women from south-east Asia were victims of sexual exploitation. Some 35 suspects were arrested and £17,455 cash was seized. Most of the women were from Eastern Europe and West Africa.

The report states: "Many of those recovered had to be sent to a Salvation Army project in Durham due to lack of appropriate accommodation in Scotland.

"Nobody has yet been convicted of trafficking in Scotland. Yet six people have been convicted of trafficking for sexual exploitation in Wales and 48 in England.

"Although Scotland should have a 10% share of UK crime figures in proportion to the population, the Association of Chief Police Officers in Scotland (Acpos) estimates that it has 13.5% of the human trafficking trade."

The report raises serious concerns about the lack of accurate identification of victims and cites examples of victims who could have gained much earlier access to support.

In 2003, Lothian and Borders police detained 14 Chinese workers after they were discovered picking cockles at Cramond Bay. At the time no offence was detected and all were released.

Two of these same Chinese workers were later arrested during the tragedy at Morecambe Bay in February 2004 where 23 trafficked workers drowned.

A Scottish Government spokeswoman said: "We have just received this report and will study it carefully and respond in due course. Trafficking in human beings is an abhorrent crime and one that the Scottish Government is committed to tackling, through partnerships with the UK Government, police and local agencies to ensure that effective measures are taken to combat this form of serious organised crime."