A type of genetically-manipulated maize which is illegal in Europe has been found by Greenpeace scientists in a consignment of maize pellets in Rotterdam port, the environmental organisation confirmed on Saturday.

The crop, Herculex, has been manipulated to produce a poison against a type of insect. Other types of GM maize were also in the pellets, which was described as GM-free on the ship's documents.

The pellets were on board the Croatian-owned bulk carrier Pakrac, which picked up its load in New Orleans, the Volkskrant reported.

Greenpeace also found a consignment of maize flour which contained 1.9% GM crops on board the same ship. The legal limit for contamination is 0.9%.

The organisation criticised the food safety authority VWA for not carrying out enough checks for GM crops. In 2005 the VWA carried out 1,582 tests and inspections on ships for GM contamination; last year it carried out just 175, Greenpeace claimed.