Hungarian authorities threatened Monday to take the owners of an alumina plant responsible for a red-mud disaster in 2010 to court if they did not deal with a new toxic red dust scare.

"(Plant operator) MAL has to act within five days of the decision issued by the authority," Zoltan Kaldi, an official from the mining authority of Veszprem in western Hungary, told national news agency MTI.

The dust from the plant in nearby Ajka, which belongs to the MAL Hungarian Aluminium Producing and Trading Company, could "seriously damage the living standards of local residents," he added.

Measurements in the area last week showed a large concentration of dust from the red sludge reservoir, well above permissible levels.

Local media reports also caused alarm among locals who had to move through clouds of visible red dust.

Samples taken over 24 hours last Thursday showed an average red dust concentration of 560 microgrammes per cubic metre (pcm) of air, far above the limit of 50 microgrammes pcm, Attila Nagy, head of the regional environmental laboratory, told MTI last week.

In October 2010, 10 people were killed and hundreds were left without a home after a reservoir at the plant burst, letting out 1.1 million cubic metres (38.8 million cubic feet) of poisonous red sludge in one of Hungary's worst environmental disasters.