Hungarian dairy farmers have marched with their cows on the streets of Budapest to protest cheap imports and tax evasion which they say are destroying fair competition and blocking their access to local markets.

A few dozen farmers and dairy workers marched their cows on Monday to the headquarters of Hungary's central tax office and other authorities to vent their grievances.

Dairy farmer Robert Laszlo said that "sales tax evasion and imported products being sold at cut-rate prices to supermarket chains" are preventing "food made with Hungarian milk" from reaching buyers.

Officials said they were cracking down on tax evasion — 18 cases totaling 13 billion forints ($47.3 million) were under investigation in the milk industry — and enforcing strict food safety standards to help domestic producers.