Raymond Martinot and his wife were the toast of the world cryonics movement. For years they were France's best preserved corpses, lying in a freezer in a chateau in the Loire valley, in the hope that modern science could one day bring them back to life.

But the French couple's journey into the future ended prematurely when, 22 years after his mother's body was put into cold storage, their son discovered the freezer unit had broken down and they had started to thaw.

The couple's bodies were removed from their faulty freezer and cremated this week. Under French law a corpse must be buried, cremated or formally donated to science. But the couple's son had vowed to go to the European court of human rights to be allowed to keep his frozen parents in his cellar. If he failed, supporters in Nederland, near Denver, Colorado, had offered to take them in.

Yesterday Rémy Martinot said he had no choice but to cremate his parents' bodies after the technical fault had seen their temperatures rise above the constant level required of -65C (-85F).

"I realised in February that after a technical incident their temperature had risen to -20C probably for several days. The alert system [on the freezer] had not worked and I decided at that point that it was not reasonable to continue," he told Agence France Presse. "I don't feel any more bereaved today than I did when my parents died, I had already done my grieving. But I feel bitter that I could not respect my father's last wishes. Maybe the future would have shown that my father was right and that he was a pioneer."

Raymond Martinot, a doctor who once taught medicine in Paris, spent decades preparing for his demise in the belief that if he was frozen and preserved scientists would be able to bring him back to life by 2050. In the 1970s he bought a chateau near Samur in the Loire valley and began preparing a freezer unit for himself. But his wife, Monique Leroy, died first, of ovarian cancer, in 1984, and was the first to enter the intricate stainless steel freezer unit in the chateau's vaulted cellars.

She remained in the freezer for almost 20 years while Dr Martinot met his high refrigeration bills by allowing paying visitors to visit the cellar. He once told reporters that ideally he would like to open his wife's freezer every day and tell her "Hello, I'm so glad to see you", but that it was better it stayed shut. He said he opened it to check it every five years. The freezer was rigged up to a generator with an alarm to alert Dr Martinot to changes in temperature or anyone opening it.

In 2002 Dr Martinot died of a stroke, aged 84, and his son followed his orders to inject him with the same anti-coagulants and store him alongside. The French courts authorised the removal and burial of the bodies. But the couple's son held firm and the bodies remained in his freezer while he continued a legal battle in France's highest court, threatening to go to the court of human rights in Strasbourg.

Many European countries have legislation restricting the preservation of dead bodies by freezing them, so cryonics enthusiasts often turn to companies in the US where it is permitted in several states.

Ben Best, president of the Cryonics Institute in Michigan, told the Guardian he was saddened and disappointed that the Martinots' freezer had malfunctioned. "The Martinot case was extremely important for us," he said. "We think cryopreservation should not be treated as a crime. France seems to be one of the worst countries for intolerance of the different ways of dealing with people who are legally dead."

His organisation had recently taken in two preserved French corpses, including the mother of a French cryonics specialist, to get around the French legal system.

David Pegg, who runs the medical cryobiology unit at the University of York, said a temperature rise to -20C would have been "disastrous" for the Martinots' corpses. "I would say even -65C was far too high," he added.