The family of Donald Moose, a Headingley jail inmate who died in 2009, is suing the Manitoba government in an effort to get answers about his death, but revised information in the case is raising even more questions.

Moose, 32, died of cardiac arrest in 2009 after becoming sick at the Headingley Correctional Centre west of Winnipeg.

In a statement of claim filed in Manitoba's Court of Queen's Bench on Sept. 27, Moose's sister, Louise Gotkin, said the family was originally told that he died from atheromatous coronary artery disease.

Then in October 2011, the provincial chief medical examiner's office told Moose's family that he actually died of an overdose of antidepressants administered by jail staff, according to the statement of claim.

That information prompted the lawsuit, as it "left the whole family feeling that this was no longer a natural death, but due to negligence on behalf of the person or persons who were supposed to protect and care for him," the claim states in part.

But the family's lawyer was informed last week that the medical examiner's office is once again going with the original cause of death, Gotkin told CBC News on Tuesday.

It's not clear how the latest development may affect Gotkin's lawsuit, which names more than a dozen parties, including the Manitoba government and the Headingley jail, as well as jail staff and pharmacists.

The suit seeks at least $2.5 million in damages and a declaration that Moose's charter rights were breached by the plaintiffs.

An inquest into Moose's death is slated to begin Oct. 29.

Earlier this year, his family's request for funding to secure a lawyer was denied.

In April, the inquest was delayed after the family alleged a conflict of interest, arguing that since Moose died in a provincial facility, the Crown cannot represent their best interests. That claim was turned down.