Heath Ledger's death was a shock for Naomi Watts

London: Hollywood star Naomi Watts said she was shaken when she learned about her ex-boyfriend Heath Ledger's death.

The star dated the actor, who died of an accidental overdose of prescription drugs in 2008, aged 28, from 2002 until 2004, reported Contactmusic.

"That was a very sad day," Watts, 48, said in a soon-to- be-aired documentary about Heath's life on Channel Seven in Australia. The production also features interviews with Ledger's family and friends, in addition to hours of home video shot by the "Dark Knight" actor.