NEW YORK — A prominent hedge fund that made huge gains betting against subprime mortgages is reportedly being investigated by federal authorities for extending a US$113 million loan to its founder so he could pay off a personal tax bill. The Wall Street Journal reported Saturday that the Securities and Exchange Commission (SEC) and the U.S. Attorney’s office in Manhattan are investigating the fund, Harbinger Capital Partners. Authorities are questioning whether the fund told investors quickly enough when it extended the loan to founder Philip Falcone last year, according to the Journal. The SEC and the U.S. Attorney’s office could not be reached for comment Saturday. Authorities are also probing whether the fund allowed some investors to withdraw money at a time when others were not allowed to because the fund was struggling. Falcone told the Journal in an interview that Harbinger did not give preferential treatment to certain investors. Hedge funds are pools of money invested by wealthy individuals and institutions like pension funds and endowments. They are only lightly regulated but have come under increasing scrutiny in recent years. In 2007, Harbinger bet against bonds that were used to finance subprime mortgages and posted huge gains when those bonds fell in value. But it began to struggle in 2008 and tightened rules about when and how much money investors could withdraw. The loan to Falcone was backed by the US$2 billion he has invested in the fund, the Journal reported.