A pilot project for frontline police officers to use Tasers should be scrapped, according to Amnesty International, after a report they commissioned found the stun guns "unlawful" and in breach of human rights.

The report commissioned by the human rights organisation concluded that the pilot scheme, being run by Strathclyde Police in Rutherglen and Glasgow city centre, should be halted

John Watson, the head of Amnesty in Scotland, has now written to Justice Secretary Kenny MacAskill calling for the end of the pilot scheme.

He said: "The provision of firearms to ordinary officers on the beat represents a major shift in policing policy in Scotland.

"We can now see that this pilot has been pushed through without due process.

"The Scottish Government should halt it immediately and replace it with a full public debate on the implications of arming the police."

Earlier this year, Justice Secretary Kenny MacAskill told MSPs that the parliament has "no locus to intervene" and that decisions on Tasers were for individual forces.

Under the pilot, launched on April 20, selected beat officers within the force are trained for three days before being issued with the powerful stun guns.

The pilot scheme follows concerns that some 4000 officers are being assaulted each year. If deemed successful, police said the stun guns would be issued to frontline officers in all 29 sub-divisions in the Strathclyde force area.

However, the Amnesty international report by Aidan O'Neill QC argues that ministers have both the legal power and responsibility to set policy in Scotland regarding the use of Tasers.

He added that the lack of ministerial guidelines in relation to a weapon that could be lethal, and therefore breach articles 2 and 3 of the Human Rights Act, is unlawful.

The legal opinion states that Article 2 of the European Convention on Human Rights suggests there has to be a clear framework governing the use of potentially lethal weapons.

The legal paper concludes that regardless of the reserved status of firearms, ministers are able and obliged to provide regulations in relation to Tasers. It also argues that ministers may direct chief constables in relation to equipment and other materials.

It also raises concerns about the lack of a policy on Tasers for beat officers from the Association of Chief Police Officers in Scotland - contrary to the position in England and Wales.

Calls by Amnesty for the pilot to be halted have been backed by Scotland's Human Rights Commissioner and Children's Commissioner.

Chief superintendent Bob Hamilton, head of territorial policing for Strathclyde Police said: "We have already invited Amnesty to come and see our training. We are doing this to prevent people from becoming injured."

A Scottish Government spokesman added: "Deployment of Tasers is an operational matter for chief constables and their use must be justifiable and necessary."