Chesapeake, the largest independent producer of natural gas in the US, paid its chief executive more than $100m in total last year, bought millions of dollars worth of his art, sponsored his basketball team and approved a $75m bonus at least one institutional investor believes was paid to bail him out of personal financial difficulties.

The details, which raised concerns about the board’s independence, emerged in company documents filed with the Securities and Exchange Commission, the US regulator, including a proxy statement filed this week, and in legal documents filed on behalf of one of the company’s shareholders.