Frans van Anraat, 63, is on trial in the Netherlands for supplying the former Iraqi regime with ingredients for nerve gas used for attacks on the Kurdish population of Iraq and Iran in the 1980s.

He is the first person to appear in court on genocide charges over the 1988 poison gas attacks on the Kurdish town of Halabja in northern Iraq.

The massacre, which killed more than 5,000 people in a single day, also features among the preliminary charges against the former Iraqi dictator, who is currently on trial in Baghdad.

On Wednesday the prosecution asked for a 15-year prison sentence for van Anraat.

In their closing argument Friday his defence lawyers argued that the Dutch court had to dismiss the case because a trial against the alleged principal perpetrators of the crimes, like Saddam Hussein, was ongoing in Iraq.

The defence also said the prosecution violated the equality principles in Dutch law because it was only prosecuting van Anraat and not one of his Dutch business partners.

Finally they argued that there was insufficient evidence to prove their client's guilt.

In the 1980s van Anraat acted as a sort of middleman buying chemicals on the world market and selling them on to Iraq despite export bans in place.

The materials he supplied included thiodiglycol and phosphorus oxychloride, both described as ingredients for mustard and nerve gases.

Van Anraat has admitted to selling the chemical components to Iraq, but maintains that he was not aware of the use to which they were put.

Under Dutch law suspects of war crimes, torture and genocide can be tried in the Netherlands even if the crimes were not committed on Dutch soil as long as the suspects reside here.

The court is expected to hand down a ruling in the case on December 23. The court will not only have to consider whether van Anraat is guilty but also if the Halabja massacre can be qualified as a genocide.