Berlin  - German authorities said Thursday they had intercepted shipments of genetically modified (GM) linseed which had apparently been supplied as a natural product to many European nations.

German laws ban products from sale unless they have been certified by state regulators. That clearance has never been issued for any GM linseed, federal officials said.

Officials in Baden-Wuerttemberg state said 16 out of 41 samples they took of merchants' linseed stocks showed them to be contaminated with small amounts of CDC Triffit, a GM strain, but added that the food was not dangerous to health.

Linseed is baked into some varieties of German bread and mixed into muesli, or pressed to making cooking oil.

The state agriculture minister, Peter Hauk, said, "We assume this does not affect just Germany, but all of Europe." He said the blend appeared to come from Canada, and demanded a ban on all Canadian linseed imports.

German environmentalists have campaigned against GM plants, claiming they have unpredictable effects on nature. Responding to such protests, Germany this year banned cultivation of MON 810, a modified maize.  dpa