The mother of a British student who died mysteriously in Germany five years ago has won the right to challenge the Attorney General’s decision not to grant her a new inquest.

Erica Duggan, 61, from Golders Green, has been fighting for an inquest for her 22-year-old son, Jeremiah, since he was found dead on a motorway in Wiesbaden on March 27, 2003, after attending a far-right event organised by the Schiller Institute.

The first inquest, in November 2003, was inconclusive and found that Mr Duggan had been in a "state of terror" when he died.

Mrs Duggen is convinced her son died as a result of his involvement with rightwing activist Lyndon LaRouche, whose ideas inspired the Institute, and she took her case to the High Court after the Attorney General refused to allow a second inquest in February.

Appearing yesterday, her lawyers successfully argued the Attorney General’s refusal should be amenable to judicial review, allowing Mrs Duggen to resubmit her case to the High Court.

Mrs Duggan said: "This is the best outcome we could have wished for. The court said we had a lot of important evidence that the original post mortem missed.

“Hopefully the application for a new inquest will now just be a formality. We are not expecting anyone to oppose it.

“We are hoping it will give a very strong message to the German authorities to help us, as up until now they have turned down all our requests for assistance.

“I feel we made history here today. But it is really shocking we have had to go through this. Why should I have to fight my own country for justice for my son?”

The new evidence submitted by Mrs Duggan included reports by three crash investigators and a forensic photographer.

The coroner's pathologist, who carried out a post mortem examination on his body on its return to the UK, said his injuries were consistent with being beaten around the head.

Lawyers for the Attorney General said his death was properly investigated.

The hearing followed a Berlin forum, held last month in the House of Democracy and Human Rights, in which families, politicians and top scholars joined forces to condemn the LaRouche Organisation and request an investigation into Mr Duggan’s death .