A scare in Japan over beef contaminated with radioactivity spread today with more parts of the country reporting tainted food, four months after March's quake and tsunami triggered a nuclear disaster.

So far, meat from 132 cattle that ate straw contaminated with high levels of radioactive caesium are known to have been shipped across the country, according to local media including national network NHK and the Asahi Shimbun.

Of the 47 prefectures in Japan, 36 of them have received meat from the affected animals, while contaminated meat is believed to have been consumed in 31 prefectures, NHK said.

The government is expected on Tuesday to ban all beef shipments from Fukushima prefecture, with the area's crippled Fukushima Daiichi nuclear plant still emitting radioactivity.

More than four months into the nuclear crisis, Japan has not set up a centralised system to check food for radiation, relying instead on testing carried out by local authorities.

Kohei Otsuka, senior vice health minister, suggested that the beef shipment ban may also be expanded to cover areas outside of Fukushima, depending on the results of investigations into the extent of the contamination.

The government has sought to assure the public that there is no immediate health threat from eating standard servings of the beef.