Prosecutors in the Netherlands said on Tuesday they will charge a 62-year-old Dutchman as an accomplice to genocide and other war crimes for supplying former Iraqi leader Saddam Hussein with lethal chemicals used in the 1988 attack on the Kurdish town of Halabja.
An estimated 5,000 civilians died in the infamous chemical attack.
Wim de Bruin of the national prosecutor's office said the man, who was arrested in Amsterdam on Monday, will face charges "for violating the laws of war and involvement in genocide."
The man was not named by prosecutors, but was identified by Dutch media as Frans van Anraat, a dealer in chemicals.
Prosecutors said the man had been a suspect since 1989, when he was arrested in Milan, Italy, at the request of the US government.
But he was later released and fled to Iraq, where he remained until 2003.
After the US-led invasion of Iraq in March 2003, he returned to the Netherlands via Syria.
The United nations suspects the man was a major chemical supplier to Saddam's regime, having made 36 separate shipments, including raw materials for nerve gas and mustard gas originating from the US and Japan.