Just one day after Mexican police announced the arrest of five suspects in connection with the brutal murder of a Canadian graduate student and her boyfriend, authorities released a video showing how they believe the couple was killed.

Ximena Osegueda, a 39-year-old PhD student at the University of British Columbia, disappeared in Mexico late last year along with her Mexican boyfriend Alejandro Honoria Santamaria, 38.

Their bodies were found in early January, half-buried on a beach in Huatulco, Oaxaca.

In the video re-enactment, a couple is shown handcuffed and kneeling on a beach, surrounded by a group of black-clad individuals who are standing behind them.

Then the man and woman, wearing only bathing suits, are stabbed in the neck by their attackers.

The video was released Tuesday, one day after the latest development in the investigation. On Monday, Mexican authorities announced the arrest of three women and two men accused of robbery, murder and participating in organized crime. Police said three accomplices still remain at large.

Authorities believe the couple was murdered by thieves who wanted the car Osegueda had recently purchased.

It was the car that led police to their new suspects. They found a receipt in the vehicle from a butcher shop, and when investigators went to the store they obtained security footage, which led to the arrest of the suspects.

Walter McKay, an expert in international crime and a former member of the Vancouver Police Department, said Mexican authorities are trying to show they are taking the crimes seriously.

He said 99 per cent of all crimes in Mexico go unsolved, and authorities are desperate to prove the country remains safe for tourists.

"I have no doubt that the Mexican government poured a lot of resources into this investigation. ...The fact that they're still on it this long after the fact indicates to me that they're taking it seriously," McKay told CTV British Columbia.

A biography on the UBC website said Osegueda taught undergraduate courses at Universidad del Mar in Mexico and was specializing in colonial Latin American literature, with a focus on Mexico, in her own studies.

She received an undergraduate degree in political science, and a graduate degree in Hispanic studies, from McGill University.

With a report from CTV British Columbia's St. John Alexander