(AFP) – Japan has seized aluminium alloy rods which can be used to make nuclear centrifuges from a Singapore-flagged ship which was carrying cargo from North Korea, a government spokesman said Monday.

The five rods were discovered on the ship during its call at Tokyo port last August and were confirmed to be aluminium alloy through tests conducted over the past six months, said Chief Cabinet Secretary Yoshihide Suga.

“The aluminium alloy is extremely strong and can be used in centrifuges, that are products related to nuclear development,” Suga told a regular news briefing.

The rods had been stored at a private warehouse and the Japanese government ordered the firm Monday to hand them over.

It was the first such handover under a special law passed in 2010 to enable Tokyo to inspect North Korea-related ships suspected of carrying materials that could be used in nuclear and missile programmes.

According to media reports, the ship was on its way to Myanmar when it arrived in Tokyo via the Chinese port of Dalian.

The spokesman confirmed the ship arrived via Dalian but said only that the cargo was bound for a “third country”.

The North has conducted three nuclear weapons tests, in 2006, 2009 and last month, and disclosed in 2010 that it is developing a programme to enrich uranium using centrifuges.

Such a programme would give it a second way to produce material for atomic weapons, in addition to its longstanding plutonium programme.

United Nations sanctions resolutions require member states to inspect cargo suspected to be linked to the North’s nuclear development.

Myanmar was suspected of pursuing military and nuclear cooperation with North Korea during long years of junta rule which ended in 2011 in the Southeast Asian state.

But the White House said last November the nation had taken “positive steps” to reduce its military relationship with the North.