Federal regulators were told about $3bn in bonuses to be paid to Merrill Lynch employees last year as Bank of America sought additional government funds to close its purchase of the bank, according to a court document.

The disclosure, made in a filing by the US Securities and Exchange Commission on Monday, sheds new light on who knew what and when, during a crucial period when BofA’s rescue takeover of Merrill teetered on the brink of collapse.