Two human rights organisations have called on Britain to amend its laws and put on trial four men accused of having taken part in the 1994 Rwandan genocide.

"Redress and African Rights call on the UK government to urgently amend its law to allow for anyone suspected of genocide to be tried in Britain", the two organizations say in a statement.

"The present UK law is out of step with international law which has made genocide an international crime since the end of World War II and therefore open to prosecution in all states, including where suspects are found," the statement reads.

The London based organisations' appeal follows last week's refusal by Britain's High Court to extradite four Rwandans to Kigali. The court found "a real risk of flagrant denial of justice" if they were to be tried by the Rwandan courts.

Other countries have previously refused to extradite suspects to Kigali but domestic legislation in place in those countries ensured that the accused were put on trial.

Arrested on 28 December 2006 in the UK, former mayors Emmanuel Nteziryayo, Celestin Ugirashebuja and Charles Munyaneza, and alleged former militia leader Vincent Bajinya, have denied any involvement in the genocide.

The latter, a doctor by training, succeeded in obtaining British citizenship under the name of Vincent Brown.

The four men are wanted by Kigali on charges of genocide and various acts of destruction and plundering.

The Rwandan genocide took place between April and July 1994 when Hutu extremists killed some 800, 000 Rwandan Tutsis politically moderate Hutu's during the 100-day massacre.