By Eleanor Bradford
Health correspondent, BBC Scotland
Scots who were infected with deadly viruses through contaminated blood are calling for a Scottish inquiry to have more powers.
Lawyers acting for hundreds of victims said an independent inquiry, set up by the Scottish Government, would only have the power to call witnesses in Scotland.
People were infected through blood transfusions and treatments
As the blood supply was contaminated before devolution, many key decision makers were in Westminster.
More than 4,000 people were infected with Hepatitis C, and in some cases HIV, through blood transfusions or haemophilia treatments before effective screening of blood donations was introduced in the early 1990s.
A separate private inquiry into contaminated blood supplies, headed by Lord Archer of Sandwell, is due to announce its findings.
Although it interviewed Scottish victims and witnesses, it had no powers to force witnesses from the Department of Health to attend because it was not set up by the UK government. Several witnesses refused to attend and documents were withheld.
Lawyer for Scottish victims, Frank Maguire, said: "All these events took place before devolution. The Department of Health had an important role to play in it, and we can't get that evidence."
High Court Judge Lord Penrose has been appointed to lead the Scottish inquiry. He has not yet set a date for the start of his investigations.
Health Secretary Nicola Sturgeon told BBC Radio's Good Morning Scotland programme the UK Government's Department of Health had given assurances it would co-operate fully with the inquiry.
"The inquiry has the maximum powers we are able to give it under the 2005 Inquiries Act," she said.
"It is the case that there may be issues of access to evidence or documents that are in possession of the UK Government but under the 2005 Inquiries Act no Scottish inquiry can compel that evidence.
"But we have been given assurances by the Department of Health that they will co-operate fully with Lord Penrose's inquiry."
She added: "Not only are we promising a full and open inquiry but we will deliver a full and open inquiry.
"I believe this inquiry is capable of giving those that have campaigned on the issue the answers they are looking for."
One of the victims, musician Andy Gunn, from Inverness, said he expected the Department of Health to withhold evidence from a Scottish inquiry, as it did in the Archer inquiry.
"Whilst we're grateful that they're holding an inquiry it's no use really because they're stopping short and withholding crucial documents and crucial witnesses," he said.
"We're not really getting to the heart of the matter. It's another whitewash."