Major Spanish dairies have been operating a scam under which the European Union has been deprived of 250 million euros in punitive fees for milk marketed after exceeding agreed production quotas, dpa reported.
Major dairies, cooperatives and smaller producers had marketed an extra 1.2 billion litres of so-called "black milk" which exceeded the quotas between 1997 and 2005, El Pais newspaper said.
The Agriculture Ministry was quoted as saying around 30 companies were involved, operating via three bogus firms which issued false invoices. Around 100 individuals were being investigated.
The report quoted police as expressing surprise to judicial authorities that the government had not taken swifter action, since the scam was "well known".