Mary-Kate to face grand jury in Ledger investigation

Mary-Kate Olsen has been subpoenaed to testify in front of a Grand Jury as investigators hope to end the mystery surrounding Heath Ledger's drug overdose death.

Drug Enforcement Administration (DEA) officials in New York are calling on Olsen, Ledger's close friend, to fill in the blanks related to the six-month-long investigation, according to US news show Access Hollywood.