The couple are now likely to take their fight to the European Court of Human Rights in Strasbourg. They were examining the judgment in detail with their legal team on Wednesday before coming to a decision.
Mr Van Colle, 63 and from north London, went on: "I think the Law Lords came to this appeal with a view, and they decided our case did not fit that view. They are perfectly entitled to that, but they should have taken more account of our case.
"This is really about money. The state is neurotic about budgets. It doesn't mind its political masters making changes but it cannot abide changes being forced on it from beneath, by the likes of us, and that is what would have happened had we succeeded. I know about how this all works because I have been a councillor for 27 years in Brent.
"There is also the legal position of witnesses. There is no special relationship. Any witness is at risk if they are threatened and the police have absolute immunity if anything happens to them. That simply cannot be right."
The Law Lords - Lord Bingham of Cornhill, Lord Hope of Craighead, Lord Phillips of Worth Matravers, Lord Carswell and Lord Brown of Eaton-under-Heywood - decided that because the case was one of theft, and that Brougham had no history of violence, Det Con David Ridley, the officer in the case, could not have known there was an immediate threat to Giles Van Colle's life.
Corinne Van Colle, Giles' 62-year-old mother, said: "We taught Giles to be an upright citizen. But if someone asked me now, I would say don't bother. Who is going to come forward after this?"
Alongside the reversal of the judgment, the couple also lost a £25,000 damages award, though they insisted that their pursuit of Hertfordshire Police was "not about money".
They have funded their actions out of their own pocket.
Giles Van Colle was educated at Haberdashers' Aske's School and City University before he opened his own optician's business in Mill Hill Broadway. He was already a rising communal star, having been elected to the board of Wembley United Synagogue as its US representative.
He was also on the US community development department's young leadership forum. His parents have
established a foundation in his memory, to back research into the visual problems of children with learning difficulties, an area in which Giles wanted to specialise.
