Open this photo in gallery On Monday, the Queen agreed to a transition period for Harry and Meghan, including their plans to divide their time between Canada and Britain while they work through the details of their future role in the Royal Family. DANIEL LEAL-OLIVAS/AFP/Getty Images

A security expert says protecting Prince Harry and Meghan, Duchess of Sussex, while they are living in Canada could cost more than $10-million annually.

Chris Mathers, formerly of the RCMP who worked in intelligence but also protection of visitors to Canada, such as members of the Royal Family and presidents, estimated the security measures required for the Duke and Duchess would be similar to those given to the Prime Minister but more costly because they would have to be set up from scratch.

“They want to live their own life as best they can and they decided this is a place that will allow them to do that. You really can’t take that away from them,” Mr. Mathers said.

Story continues below advertisement

His estimate for security costs is significantly higher than some other figures reported.

Last week, the Duke and Duchess issued a statement saying they wanted more financial independence and that they planned to split their time between Britain and North America.

On Monday, the Queen agreed to a transition period for Harry and Meghan, including their plans to divide their time between Canada and Britain while they work through the details of their future role in the Royal Family. The Queen met with Harry, Prince Charles and Prince William to address the demands made by the couple, who also said they wanted more freedom from the royal household.

Mr. Mathers, who now runs an international consulting and investigative firm, said security has changed significantly in the past few years and that Harry and Meghan will not have much control over the amount of security they would require.

The residence of the Duke and Duchesses would need to be decked out with fences, explosive-detection dogs, closed-circuit television surveillance, alarms and a security team on the ground, said Mr. Mathers, adding they would also need a team to accompany them when they leave their residence.

“They need personal body guards all the time. You have to pay those peoples’ salaries. You’ve got to pay for the vehicles they travel in and the aircraft they travel in. You have to pay for the communications equipment they require because it has to be sophisticated so that you can’t listen to it,” he said.

Mr. Mathers said the costs would double when the pair travels separately and that they would require an advance team to conduct security assessments before they go anywhere.

Story continues below advertisement

The Canadian government has been mum on its role in Harry and Meghan’s move or the anticipated costs of their security detail.

Prime Minister Justin Trudeau said in an interview with Global National on Monday that the government has not been involved “in any real way” in negotiations with the Royal Family, but that there will be “many discussions” to come.

“There’s still a lot of decisions to be taken by the Royal Family, by the Sussexes themselves, as to what level of engagement they choose to have. And these are things that we are obviously supportive of their reflections, but have responsibilities in that as well,” Mr. Trudeau said.

When asked if Canada would pay for the security costs, he said: “That is part of the reflection that needs to be had and there are discussions going on.”

The Prime Minister’s Office had no further comments to add Tuesday.

Bloc Québécois Leader Yves-François Blanchet, who has vehemently opposed paying for Harry and Meghan’s security, joked on Tuesday that perhaps Netflix could fund their protection.

Story continues below advertisement

According to the Montreal Gazette, Mr. Blanchet said he loved the series The Crown and that perhaps Netflix could launch a fourth season to cover the couples’ costs.