Ledger and Olsen, who met during the summer of 2006, were probably both friends and lovers, reports People magazine.
"Mary-Kate and Heath were casually dating for three months before Heath’s death. They were hooking up, but neither were particularly interested in making it exclusive," a source told the mag.
The two stars shared similar lifestyles, and liked to party. When they met in 2006, they were dining with friends at the Chateau Marmont in Hollywood, where Ledger was living at the time. Ledger reportedly enjoyed Mary-Kate’s sense of humour. "Mary-Kate made him laugh a lot," an eyewitness recalled.
According to police, there was an immediate link between Ledger and Olsen at the time of his death. The two had at least one telephone conversation before the star’s untimely death.