Investors including Bill Gates’s philanthropic foundation have hired forensic accountants to examine what happened to some of the money they invested in a $1bn healthcare fund for developing economies managed by Dubai’s Abraaj Group, FN's sister publication Private Equity News reports.

Four investors, who pledged about a quarter of the fund’s money, asked US advisory firm Ankura Consulting Group to audit the fund and trace their money because they want to know why some of it has not yet been used for its stated purpose of building hospitals and clinics, people familiar with the situation said.