Seven people aged between 70 and 80 appeared in court in Arnhem on Monday, charged with forming a criminal organisation and supplying a suicide powder known as “substance x” in a case set to last several days.

All seven are either members or former members of the right to die group Cooperative Last Will, which believes everyone has the right to end their lives at the time of their choosing and has long campaigned for an end-of-life pill. None have been in trouble with the police before.

The public prosecution department, however, claims several people died as a result of taking the powder provided by members of the cooperative. “They decided who could get substance X and who could not,” the public prosecutor said at Monday’s hearing. “It did not matter if  you were young or old, depressed or not.”

One of the seven, 80-year-old Loek de L, is said by the public prosecutor to have supplied the chemical compound to over 600 people via meetings at people’s homes. He bought the drug from Alex S, who was jailed for 3.5 years in 2023 for supplying the compound, known as “substance x”.

In court on Monday, Petra de Jong and Jos van Wijk, former directors of the foundation, denied being involved in supplying the drug which, said De Jong, “goes against everything we stand for”.

“We were striving for the right to die as we chose to do,” De Jong said. “Providing help was not a part of it.”

Others said all they had done was supply information. “I’ve never been involved in setting up a criminal network,” said Jos S. “It feels like I have been caught up in a bad play.”

The unnamed powder is used in the chemical industry and when ingested it can take up to 40 hours to die. Selling the powder is not an offence in itself unless the purpose is to help someone take their own life. Under Dutch law, it is illegal to help someone to die, unless a doctor acts under the strict terms of euthanasia legislation.

The foundation was set up in 2013 and now has some 30,000 members, most of whom joined when the cooperative went public about substance x.

In total eight days have been set aside for the hearings and the verdict is due in July.

Anyone struggling with suicidal thoughts can talk or chat anonymously with the helpline 113.nl or call the free number 0800-0113.