Hungarian police on Monday arrested the managing director of the company at the center of a toxic sludge disaster, as the body of the last missing person was recovered, bringing the death toll to eight.

An aerial photo taken on October 8 shows a part of the village of Kolontar. A second flood of toxic sludge from a storage reservoir at a Hungarian aluminum processing plant is "likely" after a new cracks appeared in a dike, Prime Minister Viktor Orban said. The National Investigation Office said in a statement it had "taken into custody Zoltan B., the managing director of MAL ZRT, for interrogation in connection with the mud disaster that caused the death of a number of people."

According to the website of MAL Hungarian Aluminum Production and Trade Company, its managing director is Zoltan Bakonyi.

At the same time, the body of the last person missing was recovered a week after Hungary's worst-ever chemical accident, the regional chief of the disaster relief services, Tibor Dobson told the Hungarian news agency MTI.

"The body of another victim has been found near Devecser, bringing the total to eight," Dobson said.

The two villages of Devecser and Kolontar were hardest hit when a reservoir at an alumina plant in Ajka, 160 kilometers (100 miles) west of Budapest, burst, sending a torrent of toxic sludge across an area of 40 square kilometers (15.4 square miles) and polluting the Danube and many of its tributaries.

Meanwhile, engineers, volunteers and disaster relief teams were racing against the clock Monday to finish building a new dam to contain a feared new wave of slurry from a likely second break in the reservoir walls before forecast heavy rain arrives later this week. Scene: Hungarian evacuees face long wait to return home

"The new dam is 70 percent completed" and should be finished on Monday evening, Dobson told AFP.

So far, no official estimates have been made of the total cost of the damage caused by the spill, which officials describe as the worst-ever in the country and an ecological catastrophe.

But environment state secretary Zoltan Illes reckoned MAL could face having to pay up to 73 million euros (102 million dollars).

Prime Minister Viktor Orban told parliament Monday that MAL should be called to account for the disaster and "placed under state control."

"Since it was not a natural disaster, but man-made, it won't be the taxpayer who foots the bill, but those who caused the damage," Orban said.

Illes estimated that the costs for the damage to the watercourses alone "will probably amount to 10.2 billion forint and the cost to the environment a further 8.0-12.0 billion forint."

Dead fish have been sighted as far as Tahi, which is around 40 kilometers north of Budapest, as well as closer to the capital itself. But disaster relief officials argue the fish have probably been washed along the river and are not a sign that the pollution is continuing to spread.

Indeed, alkaline levels -- a sign of water contamination -- much closer to the site of the accident are still falling.

Kolontar's entire population of around 800 people have been forced to evacuate until the construction of the second dam has been completed and the authorities give them permission to return.

"Construction work is going ahead. There were no unforeseen hiccups overnight," Dobson said.

The new dike measures 30 meters (98 feet) wide and four meters high, and will be around 1,500 meters in length when completed.

According to Illes, 600,000-700,000 cubic meters (21-24 million cubic feet) of sludge spilled from the reservoir last week, leaving 2.5 million tonnes still inside it.

Illes said it was still unclear whether MAL "overloaded the reservoirs or not. But if that is the case, it's illegal storage of waste and that constitutes a crime."

The company's three owners are among Hungary's 100 richest people, with personal fortunes of between 61 million and 85 million euros.

MAL, which was set up in 1995, posted annual revenues of 157 million euros and a profit of 715,000 euros in 2008.

With eight people confirmed dead, no-one else is missing. But 45 people remain hospitalized, with two said to be in very serious condition.