A Lebanese man with a Canadian passport has been detained on the Mediterranean island of Cyprus after a large quantity of ammonium nitrate fertilizer, which can be turned into an explosive when mixed with other chemicals, was found in his home, reports say.

The 26-year-old, who has not been named, appeared in court Thursday and remanded for eight days, according to the Cyprus Mail. The hearing was held behind closed doors for national security reasons.

“This is a case which pertains to the security of the state and public disclosure could possibly adversely affect those interests,” a public prosecutor told the judge, Reuters reported.

Two tonnes of ammonium nitrate – stored in 67,000 packages in 420 boxes – was found in the suspect’s home in the southern town of Larnaca, along with 10,000 euros in cash, the Cyprus Mail reported. It is not known what the materials were to be used for.