The global carbon market has been crippled by a cyberscam allowing fraudsters to steal and sell more than 250,000 carbon permits valued at about $5 million.
The cyber-criminals launched a ''phishing attack'', sending thousands of emails to companies around the world including Australia and New Zealand involved in the European Union's carbon trading network.
The emails claimed online security needed to be upgraded urgently.
They asked companies to re-register their trading details with the German Emissions Trading Authority, which records all carbon credits and transactions for the EU market.
Those who fell for the ploy were directed to a fake emissions registry website with the authority's logo. The scam allowed the cyber-criminals to capture security codes and passwords needed to gain access to company accounts, enabling them to steal carbon permits and resell them through trading accounts registered in Denmark and Britain.