Police in Hungary have detained a senior official of the company that owns the metals plant responsible for a reservoir which recently burst, flooding several towns with red toxic waste in an environmental disaster that left seven people dead.
Zoltan Bakonyi, head of aluminium producer MAL Zrt, has been detained for 72 hours, Anna Nagy, government spokeswoman, said on Monday.
At least seven people died and 150 others were injured in what officials quickly termed Hungary's worst-ever chemical accident which polluted an area of 40sq km as well as tributaries of the Danube river.
Viktor Orban, the Hungarian prime minister, said the company should be brought under state control because of its role in the disaster that has spoiled large areas the country's west and polluted rivers.
"We need to hold the company responsible for the red sludge spill under state control and its assets under state closure until all of these four tasks are handled," Orban told parliament on Monday.
He said a state commissioner would be appointed to take over control over MAL Zrt and manage its assets.
'War of Words'
Al Jazeera's Anita McNaught, reporting from Ajka, 160km west of the capital, Budapest, said the arrest "comes as no surprise".
"The war of words between the government and the company had been intensifying over the last couple of days," she said.
MAl Zrt has apologised for the disaster and said it will pay compensation "in proportion to its responsibility".
Our correspondent said: "The government freely admits that it could have been tougher on private business and it has not been.
"The breach of safety regulations, the lack of enforcement, the way these [company] people have been able to make money clearly at the expense of public-safety interests ... all of these things have to be pinned at the door of the Hungarian government."
According to the latest estimates, some 600,000 cubic metres of toxic sludge spilled from the reservoir at the alumina plant in Ajka last Monday.
The reservoir still holds 2.5 million tonnes of the waste.
Engineers now expect to finish new barriers to contain the sludge by Tuesday, as hundreds of volunteers, disaster relief teams and engineers race against time to erect a new dam.
"We still don't know for now whether the company overloaded the reservoirs or not. But if that is the case, it's illegal storage of waste and that constitutes a crime," Zoltan Illes, environment state secretary, said.
The environmental disaster occurred when the walls of the reservoir burst a week ago, sending a tidal wave of sludge through surrounding villages.
Al Jazeera's McNaught said that it was still not known when the remaining walls were finally going to break.
"The cracks are evident and the red sludge is there - the inevitability of this second catastrophe is beyond denial," she said.
"They have trucked in thousands of tons of dolomite rock from outside the region to try and build another obstacle in the path of this second flow which has the consistency of rice pudding - it is expected to move slowly but will be very deep and very thick."
Our correspondent said that this was not a containment exercise but it will "merely slow it [the sludge] down and buy time for the authorities to figure out how to stop it".
Illes said the government was of the belief that MAL and its directors should bear the financial responsibility for the disaster.
MAL has come under fierce criticism, with officials suggesting too much of the caustic red sludge was contained in the reservoir, but the company insists it has done nothing wrong.
The company's three owners have long featured in the lists of Hungary's 100 richest people.
Lajos Tolnay is estimated to have a personal fortune of 85 million euros, which would make him the country's 21st richest person.
His two associates, Arpad Bakonyi and Bela Petrusz, share 28th position with personal fortunes of 61 million euros each.
MAL, which was set up in 1995, had annual revenues of 157 million euros in 2008 and posted a profit of 715,000 euros.
Source: Al Jazeera and agencies