The world's fourth-biggest economy, Germany joins countries including New Zealand and France in calling for seabed mining exploration to stop until further research is done.
Buying by central banks in the third quarter took their purchases for the year to 673 tonnes, more than the total purchases in any full year since 1967.
ITSCI is a private sector scheme monitoring tin, tantalum and tungsten mines in Democratic Republic of Congo, Rwanda, and Burundi for human rights abuses.