Romania's troubled Aurul gold mine experienced problems with water long before a cyanide-rich dam overflowed, contaminating rivers flowing into neighbouring Hungary and Serbia.

Romania and Hungary are seeking compensation and international help after a cyanide leak at the end of January devastated fish stocks and threatened the water supplies of 2.5 million people.

No human health problems have so far been reported.

Australian gold miner Esmeralda Exploration, which owns 50% of Aurul, documented a number of problems in its last annual report.

These include difficulties in breaking down the material being mined with high-pressure water, and an earlier small leak from pumping equipment.

At some stages, the report says, the main treatment plant received slurry flow rates at double the intended capacity.

The Aurul mine works stockpiles of tailings previously treated for base metals, which are turned into slurry and sent to a conventional gold treatment plant.

The mine has been closed temporarily by the authorities pending the results of an investigation.

The Romanian Government owns the other 50% of Aurul, which is located near Baie Mare in north-western Romania.

Compensation

Hungarian Environment Minister Pal Pepo met Romania's Deputy Environment Minister Anton Vlad on Thursday to discuss ways of monitoring the spill and seeking confiscation.

"Romania also has enormous interest that the company which we know is responsible should be held responsible," said Mr Vlad.

Esmeralda said it doubted reports the cyanide spill had killed tonnes of fish, adding that the extreme weather which caused the spill could have also killed the fish.

"These claims cause me considerable scepticism," Esmeralda chairman Brett Montgomery said.

But Hungarian officials did not accept his explanation.

"We can count the dead fish and it's sure that the fish did not die of pneumonia," one official said.

"There is no question it was Aurul."

European dimensions

Reports from Serbia also confirm that the first traces of cyanide have been detected in the River Tisza after crossing the border from Hungary.

The Tisza flows into the Danube, which then continues to the Black Sea.

The European Union Commissioner for Transport and Energy, Loyola de Palacio, said that the spill was "a catastrophe of European dimensions".

She also said that she would try to find funds to help Hungary clean up the pollution.

Romanian experts said the cyanide concentration in the small Lapus river near the Aurul plant was 800 times the acceptable level, but it gradually lost its lethal effect as it became diluted further downstream.

The spill has been an embarrassment for Romania, which is trying to combat its Communist-era image as a serious industrial polluter in order to boost its chances of European Union membership.