Blue Bloods' Donnie Wahlberg explains key reason why Boston Blue was filmed in Toronto

Boston Blue star Donnie Wahlberg has explained why the majority of filming for the Blue Bloods spin-off took place in Toronto, rather than Boston.

The series follows Sean Reagan (played by Mika Amonsen) as he begins his career as a patrol officer for the Boston Police Department, with his father Danny Reagan (Donnie Wahlberg) joining as a detective.

However, Boston is a long way from New York and the rest of the Reagan family, meaning Danny will have to put in extra effort to work effectively with sharp and fearless Detective Lena Silver (Sonequa Martin-Green).

Despite the title, Boston Blue was primarily filmed on a soundstage in Toronto, Canada, over the summer, with only some exterior scenes shot in the famous city.

This decision led to some backlash from fans ahead of the show's debut.

Wahlberg addressed these concerns during an appearance on the Billy and Lisa in the Morning podcast, explaining that financial constraints prevented more filming from taking place in Boston.

He recalled: "When I initially was offered the job, I said, 'We got to go to Boston.' They said, 'We can't afford it.'"

However, the 56-year-old actor didn't accept this without a fight, adding: "It's basically thirty cents on a dollar to film in Canada right now, compared to eighty cents on a dollar, ninety cents from a dollar even with tax breaks.

"But I said, 'We have to go to Boston. I can't not go to Boston.'

"And so the plan right now is to do the interiors up here [in Toronto] and go to Boston every couple of weeks and do what we did and put a crew together, a Boston crew, and go down and film all over the city.

"You can't fake what Boston looks like. And you know, we're bringing Boston actors up here to guest [star] in the show.

"We're doing everything we can, and hopefully, in success, we can be in Boston more. The aim is, let's compromise to get the show made.

"We'll work outside and do exteriors in Boston, and then you know, in success, perhaps we can come down there and be there full time. That would be a dream of all dreams."

Several key Boston landmarks have already been confirmed for the series though, much to fans' relief, including Fenway Park, Granary Burying Ground and various other locations around downtown Boston.

Boston Blue premieres on Friday, October 17, on CBS.