A 74-year-old woman and a 76-year-old man have been convicted for their involvement in supplying a chemical compound known as “substance X” that a judge said led to several suicides.

The two are members of the right-to-die campaign group Coöperatie Laatste Wil (CLW). The judge held them responsible for supplying X and providing information about the drug. Both were given suspended prison sentences.

In all, six suspects – all over the age of 70 – were tried, but the other four were acquitted.

Although euthanasia is legal in the Netherlands, only a doctor may help end someone’s life at their request, under strict conditions. It is illegal for anyone else to assist or cause someone’s death.

Substance X, used in the chemical industry, has been touted by campaigners who believe in a right to end their own lives as a pain-free poison. But experts have said it can take people up to 40 hours to die.

The court ruled that trading in substance X was equivalent to participating in a criminal organisation and ruled that the two convicted seniors played an active role in selling the substance, arranging price agreements and distribution.

One woman was handed down a suspended prison sentence of one year and a probationary period of three years. She was also sentenced to 80 hours of community service. The judge hoped the “strong suspended sentence” would act as a deterrent to her and others who are thinking about committing similar crimes.

The man, the former chairman of CLW, received a lesser suspended prison sentence of four months with a probationary period of one year, with the judge finding he had a smaller role.

Prosecutors had asked for 2.5 years in prison for both, with one year suspended. The suspects said in their defence that they were acting to help people.

Related deaths

Of the seven people originally charged in the case, 80-year-old Loek de Leeuw died in April “from the stress of the protracted court case”, his daughter told the Volkskrant. A second suspect, a 77-year-old man, committed suicide earlier this week before the verdict was announced.

Research by the GGD Amsterdam and the Suicide Prevention Foundation has found that since 2015, at least 172 people in the Netherlands have died after using substance X. Their average age was 59 years old.

While selling the powder is not an offence in itself, under Dutch law, it is illegal to help someone die. Only a doctor can assist someone to end their life, following the strict conditions of euthanasia legislation, which include unbearable suffering with no hope of improvement.

Anyone struggling with suicidal thoughts can chat with someone anonymously online at www.113.nl or call the free number 0800-0113.