The inspections started after a milk cow in Tokyo's neighbouring prefecture had tested positive.

The Farm Ministry together with a panel of experts officially confirmed it was Japan's 5th case of the brain wasting disease. Officials of Kanagawa Prefecture's health department inspected nearly 50 cows raised at the same farm of the 6 year-old hostein, caught with the mad cow disease.

The farm owner was questioned on what the cows were fed and inspectors were also trying to find out whether the infected cow had been transferred from another farm.

The first case of mad cow disease was reported last September, seriously hurting Japan's beef industry.

Since then, two cows tested positive in November, and another in May.

The four cows were found to have been born in the same year and in Hokkaido northern Japan.

It is still not know if they were fed on the same kind of substitute milk.

The incident triggered an outbreak of corruption cases with businesses trying to take advantage of the Farm Ministry's buy-out scheme of left-over domestic beef.

More recently, Japan's largest sausage company - Nippon Ham - reportedly labelled imported beef as domestic, in an attempt to cheat the government.

These incidents only served to dampen consumer confidence.

"It makes you afraid of eating meat. I wish there was a way to be able to eat meat safely," one unidentified woman said.

Another man remarked: "I am worried and I just hope that the Agriculture Agency will investigate the case thoroughly."

A recent survey showed that as many as one in four Japanese have stopped eating beef and analysts warn that the 5 cases discovered so far may just only be the tip of the iceberg.