Nicholas Rodrigo Hovanesian, 24, of Calgary, is wanted on three counts of first-degree murder. (Calgary Police Service)

Calgary police have issued a Canada-wide arrest warrant for a fourth suspect in the New Year's Day shooting deaths of three men.

Investigators are looking for Nicholas Rodrigo Hovanesian, 24, who faces three counts of first-degree murder.

At least three masked men opened fire in a southeast restaurant on the afternoon of Jan. 1, killing Sanjeev Mann, 22, and Aaron Bendle, 21 — who police said had links to organized crime.

An innocent bystander, Keni Su'a, 43, was also eating in the establishment and tried to escape but was gunned down in the parking lot of the strip mall. Police said the attackers beat him before he died.

Hovanesian is described as Hispanic, about five-feet-11 and about 150 pounds. He has black hair and brown eyes.

"He is known to our gang unit as an associate but he has not been designated a gang member by the courts," said Staff Sgt. Doug Andrus of the homicide unit on Monday.

Investigators said Hovanesian has connections to both Calgary and the Lethbridge area.

"We don't know his whereabouts and that's why we're releasing the information in hopes that people with information will come forward," said Andrus.

3 men already charged

He cited investigative reasons for not disclosing how police investigators believe Hovanesian was involved in the shootings, or if he was even at the scene.

When asked if the public should consider Hovanesian armed and dangerous, Andrus replied, "I think you have to look at the facts and the incident that he was involved [in] and act appropriately."

Since June, Calgary police have arrested three men in the case.

Nathan Zuccherato, 22, Michael Roberto, 25, and Real Honorio, 25, have all been charged with three counts of first-degree murder.

Andrus would not say if the three accused are co-operating with the case, but said police continue to investigate the killings as a high priority.

"This is an ongoing investigation and we are striving to identify the individuals involved in the incident and hold them accountable," he said.