BERKSHIRE Hathaway, the insurance and investment firm run by billionaire Warren Buffett, has said second-quarter profit rose 62% as investments benefited from higher US interest rates and a weakening dollar.

WARREN Buffett’s Berkshire Hathaway Inc, which is under investigation for its role in improper reinsurance accounting at American International Group Inc, said over the weekend that the American government is inquiring about its own books.