STOCKHOLM, Jan 30 (Reuters) - Iranian traffickers, trying to dodge an embargo imposed by Western nations over Iran's nuclear programme, are smuggling weapons on container ships owned by firms from the countries that imposed the sanctions, a think-tank said on Monday.
Before 2008, when the United Nations toughened arms embargoes on Iran, the majority of arms and dual-use goods shipments to and from Iran were being transported aboard Iranian ships, or ships chartered by Iranian companies, it said.
"By using respectable mainstream European shipping companies in countries such as Germany and France, they make them their unwitting accomplices," said Hugh Griffiths, a researcher at the Stockholm International Peace Research Institute.
Container shipping companies generally cannot verify the cargo they transport in the sealed containers.
The owners of the vessels appear to have been unaware of the nature of the illicit cargo, said SIPRI, which conducts independent research on international security, armaments and disarmament.
The international community's biggest concern is the smuggling of items that Iran might use for any production of nuclear weapons - which the West suspects is the goal of Iran's nuclear enrichment programme. Tehran says the programme is for purely peaceful purposes.
"What has been seized and is in our report is just the tip of the iceberg," said Griffiths.
"Like the Colombian cocaine cartels, they have in recent years come under increased pressure from a legal framework that allows their cargoes to be seized. So they have started to use ships which have no suspect profile," said Griffiths.
SIPRI said governments should discuss with the shipping industry ways of tackling the growing use of container shipping for smuggling.
"We suggest there should be more information sharing between the shipping industry and governments, because the shipping industry has a lot of valuable and currently untapped information - particularly ship security officers and the captains of certain ships," Griffiths said.
CMA CGM, the world's third-largest container shipping group, said in November it had stopped export shipments from Iran and was scanning all containers bound for the country.
(Reporting by Anna Ringstrom; Editing by Alison Williams and Tim Pearce)