On October 4, 2010, a corner of a reservoir of alumina company MALʼs plant in Ajka, Veszprém County, housing red sludge – a waste product of the process refining bauxite into alumina – collapsed, freeing approximately one million cubic meters of waste. The mud was released in a wave that flooded several nearby settlements, including the village of Kolontár and the town of Devecser. Ten people died, and 150 were injured.

MAL was fined HUF 135 billion for environmental damage caused by the spill and was later forced into liquidation.

Among the defendants the court found guilty on Monday were former MAL CEO Zoltán Bakonyi and his deputy, who were sentenced to two-and-a-half years and two years, respectively, in prison. Six more defendants were handed down suspended prison sentences, while one was ordered to pay a fine and one received a reprimand. The other five defendants in the case were fully acquitted. 

Charges were initially brought against the 15 defendants in January 2012. A court in Veszprém acquitted all of them in a ruling issued in January 2016, but an appeals court overturned that ruling in February 2017 and ordered a retrial.

Prosecutors argued that the original verdict was marred by procedural irregularities, and that the red mud spill could have been avoided if the firmʼs management had intervened without delay, according to a report by Chinese news agency Xinhua.