More than 3500 Sri Lankan police officers - including some senior commanders - have received training from the Scottish Police College (SPC) since 2007 through projects funded by the UK and Scottish governments.
An investigation by not-for-profit research group Corporate Watch also found the SPC is involved in spearheading a project to help to set up a National Police Academy in Sri Lanka. Most of the training involves Scottish officers travelling to the island, but in some cases Sri Lankan police are brought to Scotland.
Amnesty International in Scotland has details of Sri Lankan police assisting government commandos who opened fire on civilians, and the murder of detainees in police custody.
UN High Commissioner for Human Rights Navi Pillay last week launched an attack on the Sri Lankan government's human rights record following a week-long visit, citing police intimidation of priests, journalists and human rights advocates. Pillay also talked of dissenting voices being "permanently silenced".
Phil Miller, from Corporate Watch, said: "She reported the country was heading in an increasingly authoritarian direction and complained about how the police had been harassing people who she had been trying to interview.
"The police were prepared to be abusive even when the UN was there and it's the Scottish Police College who have been doing a lot of training over the past six years.
"I think that raises some quite serious questions. If the country is going in a more authoritarian direction and Scottish police have been helping train the Sri Lankan police for the past six years, are they just helping to develop the police state? Do they have any concerns that this project isn't working?"
The training by Scottish police officers took place both before and after the government's final counter-insurgency campaign against the Tamil Tiger rebels in 2009.
A recent UN report suggested that as many as 70,000 civilians died in the last few months of the war, mostly killed by government forces.
Campaigners say major concerns still remain over the country's human rights record.
Mark Bevan, programme director for Amnesty International in Scotland, said: "Unlawful detentions, torture, and enforced disappearances remain rife in Sri Lanka and go unpunished. It's shocking to think similar activity may have taken place while Scottish Police College training work and Scottish police officers were in the country.
"We would urge the college to investigate its engagement with the Sri Lankan police force and review their activity in light of Navi Pillay's report.
"Furthermore, we would expect them to take the strongest measures possible to ensure any Scottish police staff working with or in Sri Lanka to strongly condemn violations of human rights and in no way contribute to or suppresses reporting of these brutal violations."
A spokesman for Police Scotland said the SPC had an international reputation for the quality and integrity of its training packages, which are delivered in Scotland and across the world.
He said: "When the British Government supports justice and security projects, there are safeguards put in place to ensure any work does not contribute to human rights abuses and it has been clear from the outset that the training reform package in Sri Lanka, led by the SPC, aims to embed international standards in police training.
"There has also been widespread support for the project from opposition parties, UN and international humanitarian agency representatives, and non-governmental organisations."
The Scottish Government confirmed it funded a £400,000 training project which came to an end in March, with more than 3500 Sri Lankan officers receiving training.
A spokesperson said: "The aim of this project was to use the extensive expertise of the Scottish Police College and other agencies to develop a new model of community policing to help promote human rights in Sri Lanka. Sri Lanka is now classed as a middle income state. The decision to end funding was taken to allow the Scottish Government to focus on projects in poorer countries."
The Foreign Office said the Scottish Police College received funding of £236,042 from April 2007 to March 2013 for work in Sri Lanka via the Conflict Pool fund, which aims to reduce the impact of conflict and instability around the world.
A spokeswoman added: "Our police training reform project in Sri Lanka, led by the SPC, aims to embed international standards in police training.
"Opposition parties, UN and international humanitarian agency representatives, NGOs and others have indicated their firm support for our project."
She added: "Reform projects such as this one take time. We believe that our continued support will have a positive impact, in the interests of all of Sri Lanka's communities."
For Corporate Watch report go to www.corporatewatch.org/?lid=5009