Troubled American football star Aaron Hernandez has been slapped with two murder charges over allegations he was involved in a bloody drive-by shooting in Boston, Massachusetts in 2012.

The former New England Patriots player has been indicted on two counts of first-degree murder stemming from the killing of Daniel Abreu and Safiro Furtado, who were shot dead in Boston in July, 2012, according to the Boston Globe.

The pair was allegedly gunned down in a car as they waited at traffic lights.

The news comes just months after Hernandez, 24, pleaded not guilty to another first-degree murder charge as part of a separate case. He denies shooting his former friend Odin Lloyd, whose body was found at an industrial park near the sportsman's Massachusetts home last June (13).

Hernandez is being held without bail.