Sovereign wealth funds, investment schemes owned and controlled by states, have poured more than $8bn (€5.5bn) of capital into private equity funds and their management companies in the past five months, according to research by Financial News.

The news follows comments by David Rubenstein, co-founder of US private equtiy firm the Carlyle Group, who said at a conference in Hong Kong this week that private equity would have to look at fresh sources of funding, such as SWFs, to counter the effects of a possible drop in returns as a result of the credit crisis.