Swiss police say they have detained several people and opened a criminal case a day after the first use of the “Sarco” capsule to end a person’s life. Assisted dying is legal in Switzerland in some circumstances.

Police in the northern Swiss canton of Schaffhausen said on Tuesday that several people had been detained, and a dead body taken for examination, following the apparent first use of a capsule designed to help people end their lives.

The “Sarco” capsule, made in the Netherlands and in development for several years now, is supposed to allow a person reclining inside to press a button, after which most of the oxygen in the sealed chamber is replaced with nitrogen.

According to the group that promotes its use, Exit International, this triggers first mild disorientation and euphoria, then unconsciousness, and in a few minutes death by asphyxiation.