Jeremiah had travelled to Germany to what he thought was an anti-war rally
The family of a 22-year-old student who died in Germany five years ago are petitioning the government to intervene in the case.
Jeremiah Duggan was hit by cars on a motorway shortly after ringing his mother appealing for help. A German coroner recorded a verdict of suicide.
British coroners later said Mr Duggan, from Golders Green, north London, was in "a state of terror" when he died.
Campaigners want ministers to lobby the German government to reopen the case.
Mr Duggan was found on a motorway in Wiesbaden on 27 March, 2003. German police said he had run into the path of two oncoming cars.
His family say he had travelled to Wiesbaden from Paris, where he was studying, to attend what he believed was an anti-war rally organised by the Schilling Institute.
The institute was described by the Duggan family at the British inquest into Jeremiah's death as a "dangerous and political cult with strong anti-Semitic tendencies, known to have a history of intimidation and terror tactics".
Hornsey coroner Dr William Dolman said he was unable from the outset to accept the conclusion by the German authorities that Jeremiah had intended to take his own life.
He instead recorded a narrative verdict, saying the student had received fatal head injuries when he ran into the road and was hit.
He also declared at the end of the inquest that there were still many unanswered questions about his death.
Mr Duggan's mother, Erica Duggan, said: "We asked for a fresh inquest and I made a full statement to the Attorney General providing evidence of how there has been no proper investigation in Britain or Germany.
"What more can the individual do when states prefer to cover up what may well be crimes? My last hope is to put these facts before our Prime Minister Gordon Brown."