Police referred to prosecutors Tuesday a 23-year-old man suspected of producing the same explosive used in the terrorist attacks in Paris in 2015 and one in Brussels last year.
The man, whose name has not been released, is suspected of making a small amount of triacetone triperoxide, known as TATP, at his home in Ichinomiya, Aichi Prefecture, in February last year, according to the police.
He posted on YouTube last year footage showing how to make the explosive from chemicals and drugs sold in stores. The three-minute video has been deleted.