Police investigating the fatal shooting of a reputed Canadian gangster in Mexico fear there may be retribution for his death -- at home, and abroad.

Thomas Gisby was gunned down on Saturday morning at a Starbucks in Nuevo Vallarta, just north of the western resort city of Puerto Vallarta, police say.

RCMP allege the 50-year-old was a "high-ranking organized crime figure" involved in drug trafficking and other illegal activities.

In the wake of his death, police fear that someone may try to exact revenge.

"It is an organized crime target in British Columbia that was killed. It was not simply a tourist or an individual down there," RCMP Chief Supt. Dan Malo told reporters in Surrey on Saturday.

Gisby headed up a criminal organization in B.C., which police referred to as the Gisby Crime Group, said Malo. The group allegedly had ties to other criminal organizations.

"Police are going to be paying particular attention to this group here in the foreseeable future to see what impact (Gisby's death) has," said Malo.

Gisby has also been linked to the Hells Angels and the B.C.-based Dhak gang. Many members of the latter group have been killed in recent months in a series of tit-for-tat shootings, Vancouver Sun reporter Kim Bolan told CTV News Channel.

Police are exploring whether Gisby's death involved a criminal organization, she added.

An investigation by Mexican authorities is in its early stages and police in Canada have said it's unclear who is behind Gisby's murder.

"Details are a little bit sketchy, there's been no suspect named. No motives given for what happened," said Mexico-based freelance reporter David Agren.

Reports indicate two patrons who were sitting in Starbucks jumped up while Gisby was waiting in line and shot him point-blank, Agren told News Channel on Sunday.

He noted that one account of the incident says the assailants fled in a Volkswagen Jetta, while another says they got away in a public transport vehicle.

In a separate interview with CTVNews.ca, Malo said drug dealing and illegal gun trading were among Gisby's activities. He had a criminal record dating back to the 1990s.

State authorities have said Gisby was living in a development known as Green Bay next to a golf course in Nuevo Vallarta, said Agren.

With files from CTVNews.ca's Sonja Puzic