The mustard gas found in a storage room of a block of flats in Ede last October was made by the tenant – a former chemistry teacher, the public prosecution department said on Thursday.

The man had written a note for his family before he died informing them about his unusual hobby and how to dispose of the chemicals. In total, officials found 56 different chemicals stored in the flat and cellar.

Of all the substances examined, only the mustard gas was illegal, the public prosecutor said.

The man had bought the chemicals and stored them himself and was well aware of the dangers, the public prosecution department said. Nevertheless, ‘this was a hobby which had become seriously out of hand with serious risk to both himself and his surroundings,’ the statement said.