Prime Minister Stephen Harper must engage in a "high profile" diplomatic effort in order to save the life of a Canadian man facing a public beheading in Saudi Arabia, relatives said through a spokesman Friday.

Earlier this week, a Saudi court turned down an appeal for Mohamed Kohail, 23, who earlier this year was convicted, along with two other males, of killing a man during a schoolyard beating.

Now, the Kohail family believes intervention by Saudi Arabia's King Abdullah, who could order a new trial, may be their son's only hope.

"It's very unlikely that the King intervenes in such matters without high profile diplomatic communication," said family spokesman Mahmoud Al-Ken.

He added that both Harper and Foreign Affairs Minister Lawrence Cannon need to get involved.

In March, Kohail was convicted for his part in the beating death of youth worker Munzer Al-Haraki at Jeddah's Edugates International School on Jan. 13, 2007.

In an interview with CTV Newsnet, Al-Ken said the family has exhausted all the legal procedures in the Saudi system and he said the trial did not meet international standards for fairness.

"Court sessions lasting 10 minutes, no cross examination of witnesses, no legal representations," said Al-Ken of the trial.

Still, though the king can order a retrial, only the victim's father can grant clemency in the Saudi system, said Al-Ken.

Dubai-based reporter Sonia Verma told CTV Newsnet that Kohail must have the decision overturned by the Supreme Judicial Council.

But she said that outcome is very unlikely.

"The Supreme Court has to essentially approve the appeals court decision," Verma told CTV Newsnet in a phone interview on Friday.

"Most decisions are simply approved; it's a matter of rubber-stamping. And then the decision goes up to the king. So, that's the process."

Lisa Monette, a spokeswoman for the Department of Foreign Affairs and International Trade, said Ottawa could not confirm that a ruling had been handed down by the appeals court in Saudi Arabia.

"Our latest information is that the Court of Cassation (appeals court) has not yet delivered a verdict on the most recent appeal," she said.

Monette said Foreign Affairs Minister Lawrence Cannon "has been briefed on the case" and it is his intention "to speak to his Saudi counterpart in the very near future to reiterate our concerns."

She said the government is doing everything it can to help Kohail and his teenaged brother, Sultan, who has also been convicted for his part in the fatal schoolyard beating.

But it is not only Mohamed Kohail who could be executed.

In April, Sultan Kohail was convicted for his part in the same fatal beating -- but being a youth, he received a lighter sentence than his brother.

His sentence was to receive 200 lashes and spend a year in jail. However, a court later decided he should be tried as an adult.

According to The Globe and Mail, the younger Kohail will be re-tried next week. If convicted, he, too, could face a penalty of death.

Both brothers immigrated to Canada with their family in 2000.

The Kohail family lived in Montreal until 2006, when they returned to Jeddah after a family member became ill.