Shipping containers are passing unchecked through Rotterdam harbour because of a problem with its computer system, Dutch media have reported.

The AD quoted sources at the docks saying that customs officers were approving perishable commodities such as fruit by e-mail because they were unable to carry out electronic checks. Drug smugglers are known to favour commodities such as bananas and pineapples precisely because of the need to send them through customs quickly.

One logistics firm claimed that under the emergency procedure consignments were being passed almost instantly, without proper checks. The system has been in force for at least two weeks, the source said.

The Dutch customs agency confirmed that it was experiencing computer problems but denied that unchecked consignments were passing through unchecked. ‘The risk assessments are constantly being revised, but currently this is being done by hand,’ said spokeswoman Gera van Weenum. ‘It is taking longer, but not all containers contain items that don’t belong there.’

A source within the agency told the newspaper that drug traffickers were aware of the problem. ‘They will try to profit from it. We can’t bring in extra staff because there aren’t any,’ he said.