The Dutch Supreme Court has upheld the war crimes conviction of a timber dealer who was found guilty last year of selling arms to former Liberian leader Charles Taylor and of complicity in war crimes committed by Taylor's forces in Liberia and Guinea from 2000 to 2003.

Guus Kouwenhoven was first convicted of arms smuggling in 2006 but later cleared on appeal. He was convicted in April last year based on new evidence and sentenced to 19 years in prison.

The Supreme Court on Tuesday rejected an argument by Kouwenhoven's lawyer that Dutch courts couldn't prosecute him because of an amnesty Taylor proclaimed in 2003 shortly before stepping down as Liberia's president.

Kouwenhoven was detained last year in South Africa and is awaiting extradition to the Netherlands.