Prosecutors in the Netherlands are investigating the deaths of at least 33 people who may have used a chemical substance to end their lives via encrypted email and messaging platforms.
The substance - which has been named 'suicide powder' in the media - came from a member of a right-to-die Dutch group, authorities said on Wednesday.
The powder helps people end their lives if they do not meet strict doctor's conditions for euthanasia, which is permitted under certain conditions in the Netherlands.
The allegations emerged during the trial of several members of the group calling itself Coöperatie Laatste Wil (Cooperative Last Will).
A 28-year-old suspect, Alex S, was arrested for selling the powder -- also known as "substance X" -- in July and is on trial on charges of money laundering and violating medical laws.
Until prosecutors had believed only six people had consumed the fatal powder.
But authorities now believe that as many as 33 people may have died after buying the drug and at least 15 of them had used "Substance X".
The court heard that the suspect used messaging platforms such as Telegram and the encrypted email service ProtonMail to sell the powder online for between €20 and €30.
The Netherlands was the first country in the world to legalize euthanasia and medically approved physician-assisted suicide in 2002.
At least two doctors must agree that a patient is experiencing "unbearable and endless suffering," with no prospect for improvement, and must repeatedly ask to die while of sound mind.
In court, Alex S said that he believed everyone should be able to "determine our own destiny".
Last month, Dutch authorities also arrested the chairman of Cooperative Last Will on suspicion of illegal assisted suicide and participation in a "criminal organisation". He had told Dutch media that he had sold "Substance X" to "over one hundred people".
Assisted suicide is punishable with a jail term of up to three years in the Netherlands.