A HEDGE fund manager in America shocked Wall Street by announcing that he had bought significant stakes in two healthcare companies without even noticing.

Scott Sacane, who runs Durus Capital Management in Connecticut, admitted last week that he had ‘inadvertently’ acquired 78.5 per cent of Aksys, which makes dialysis equipment, and 33 per cent of Esperion Therapeutics, specialising in treatment for heart disease.

Each stake would have cost Sacane about $150 million (98 million).

Sacane said there had been a breakdown of internal controls at Durus Capital Management.

He informed the Securities Exchange Commission, America’s financial regulator, on Tuesday.

William Dow, Aksys’s chief executive, said: ‘It is unbelievable.’

This is not the first time that Sacane has made ‘inadvertent’ purchases.

In April, he told Aksys that Durus had mistakenly bought 19.5 per cent of the company.

He agreed to reduce his stake below 15 per cent over the next two years.

Instead Sacane went on a buying spree increasing his original stake more than fourfold.

Esperion warned Sacane in November that buying large blocks of shares required board approval but, according to his submission to the Securities Exchange Commission, Sacane carried on buying.

Esperion and Aksys are now trying to work out how Sacane can reduce his stake without sending their share prices into freefall.