The lawsuit was filed on behalf of 235,000 individuals and organisations, and alleges that BHP Billiton, as it was called then, ignored warnings prior to the dam collapse.
The Samarco iron ore project in Brazil is owned jointly by BHP and by Vale, Brazil’s iron ore champion, itself under scrutiny for the more recent disaster of earlier this year at Brumadhino.
The lawsuit argues that production was boosted at Samarco to boost sales to compensate for a decline in iron ore prices, a practice which was common to all the majors at the time.
However, the lawsuit goes on to argue that the capacity of the dam at the Samarco operation also had to be increased, by raising its height, and that this was done so in the face of warnings from engineers.
It’s further alleged that cracks that appeared in the dam were early signs of rupture, but that these were disregarded.
When the dam burst, the resulting torrent of mud killed at least 17 people.
In August, BHP reached an agreement to settle a class action complaint filed in the US.
Action in Brazil is ongoing.
The UK suit is seeking US$5bn in damages.
On the day, BHP shares traded down by less than one percent to 1,751p in the context of a generally weaker market.
Traders were broadly speaking unphased by news of the lawsuit, since it had been widely expected.