The restaurants in the canton of Jura were found out by “A Bon Entendeur”, the consumer affairs programme, which tested 15 of the raw meat meals from restaurants in western Switzerland.
“One can properly talk of obvious and blatant deceit,” said, a cantonal chemist who analysed the phoney steak tartar.
Only four of the meals tested were found to be free of elevated levels of bacteria, the programme said.
Two plates of steak tartar found in restaurants in the canton of Vaud were found to be particularly infected, exceeding many times over the acceptable levels for bacteria.
Following the scandal over horsemeat fraud which hit Europe in February, the Swiss federal government tightened regulations to improve the traceability of where food stuff has come from.
The goal is to be able to document all stages of food production, transformation and distribution, the ATS news agency said.
In February, horsemeat was discovered in a range of frozen lasagne products distributed across Europe that advertised using beef.
As of January, Switzerland will follow European Union standards for tracing food products.
However, Swiss law makers have stopped short of making public lists of restaurants with questionable hygiene, ATS said.
The senate recently rejected the idea, while opposing a proposal from the lower house of parliament that would let customers check the official “certificate of conformity” of a restaurant.