In a shocking turn of events more than four years after HEATH LEDGER’s death from a drug overdose, his extended family and friends are calling for MARY-KATE OLSEN to reveal what really happened that night!

The 25-year-old actress was reportedly involved in a budding romance with the Australian hunk and sent her own security guards to his apart­ment when his lifeless body was discovered.

But Mary-Kate has never spoken publicly about the 28-year-old “The Dark Knight” death, and his distraught loved ones feel it’s time for her to speak up.

“We don’t know enough about the exact circumstances of Heath’s death,” Richard Syme, a cousin of Heath’s father, told The ENQUIRER in Australia.

“Prescription drugs and all sorts of things were found in his apartment, but Mary-Kate Olsen didn’t ever go on the record to talk about what happened. It would be good if she did.”

Ledger’s parents remain devastated, and while his mother Sally told The ENQUIRER she’s still too distraught to speak about their loss, his childhood friend Ben Rogers agrees that it’s time Mary-Kate talked.

“She never made a state­ment, and there is a plethora of unanswered questions,” Rogers told The ENQUIRER.

“A lot of people are wondering about her point of view and her version of events. Mary-Kate needs to clarify what she knows for his family.”

The former “Full House” star met Ledger in March 2006 and the two reportedly grew close in the months before his death. They were often spot­ted strolling and cuddling around New York’s SoHo neighborhood, where they lived just two blocks apart.

The actor’s body was discovered in his $23,000-a-month rental apartment on Jan. 22, 2008, by masseuse Diana Wolozin.

According to police reports, Wolozin placed two calls to Mary-Kate from Ledger’s phone before dialing 911.

The actress was 3,000 miles away in California but told Wolozin she was dispatching her own security guards to the scene.

In reports, Ledger’s neighbor Joseph Cotto said Mary-Kate’s security arrived before the police.

New York Police Department detectives did not immediately interview the actress, and her lawyer seemed to respond to anonymous and unsubstantiated claims that Mary-Kate would not cooperate without a promise of legal immunity.

“We have provided the government with relevant information including facts in the chronology of events surrounding Mr. Led­ger’s death and the fact that Ms. Olsen does not know the source of the drugs Mr. Ledger consumed,” her attorney Michael C. Miller said in a statement.

Mary-Kate has not publicly commented on his death other than calling Ledger a “friend,” but a source said: “If Mary-Kate can come forward as Heath’s family and friends want, it may serve as closure and they all can get on with their lives.”