WINNIPEG -- A Manitoba man who spent 23 years in prison for first-degree murder has had his conviction quashed.

Three judges from the province's Court of Appeal have ruled that Frank Ostrowski was denied important information that could have helped his defence when he was convicted in 1987.

Ostrowski was found guilty of ordering the fatal shooting of a drug dealer based largely on the testimony of a key witness -- Matthew Lovelace -- who had separate charges of cocaine possession stayed in exchange.

Ostrowski's lawyers and the jury were never told about the deal and Lovelace told the trial he did not receive any favours in exchange for his testimony.

Earlier this year, Crown attorney Randy Schwartz told court that the trial was unfair and Ostrowski's conviction should be overturned.

Ostrowski's lawyer wanted the Appeal Court to go a step further and formally acquit Ostrowski, now in his late 60s.

The court decided to quash the conviction, order a new trial and enter a judicial stay of proceedings.

"There is a significant amount of other evidence that supports the details provided by Mr. Lovelace, such that it would remain open to a jury to find his testimony about the accused credible and reliable," Justice Holly Beard wrote on behalf of the three-member appeal panel.

"It is not clearly more probable than not that the accused would be acquitted at a hypothetical new trial."

However, with all that has happened, a new trial is not warranted, Beard wrote in a judgment released Tuesday.

"Given the length of time that has passed since the events at issue, including the trial, and the significant amount of time that the accused has already spent in custody, I agree that there should be a judicial stay of proceedings regarding the new trial, and I would so order."

Ostrowski maintained his innocence throughout his incarceration. In 2009, a Court of Queen's Bench judge cited serious concerns with the conviction and released Ostrowski on bail.

In 2014, then-federal justice minister Peter MacKay ruled the case a likely miscarriage of justice and ordered the Manitoba Court of Appeal to review it.