Agrochemical giant BASF has blamed human error after unauthorised genetically modified potatoes were found growing in a field.

The admission came as the EU Commission summoned the German company to a hearing following the blunder.

Small quantities of BASF’s GM Amadea potato were found in Amflora fields planted in Sweden.

BASF said “extremely small quantities” of Amadea potatoes in Amflora fields had been found during regular in-house checks.

The level of contamination was less than 0.01% – equivalent to 47 Amadea plants among approximately 680,000 Amlora plants.

The cause of the low level co-mingling of Amadea is being thoroughly analysed, said a BASF statement.

“The co-mingling was identified because Amadea flowers are white, while Amflora only develops a few violet flowers.

“All Amadea plants have been removed during the growth period and did not enter the commercial starch production.”

Amflora fields in Germany and the Czech Republic were also monitored in the course of the regular stewardship controls.

No Amadea potatoes were identified in these fields.

But Greenpeace EU agriculture policy advisor Stefanie Hundsdorfer described the situation as a deplorable lapse in bio-security.

“Who knows what the effects of growing a largely untested GM crop for months in the open environment will be?”

The Swedish authorities should order all plants in the contaminated fields destroyed, said Ms Hundsdorfer.

“BASF should test all Amflora fields and destroy all plants where contamination has occurred.”