SAINT JOHN, N.B. -- A warrant has been issued for a couple wanted in a daring New Brunswick diamond theft that has been connected to a series of similar heists nationwide.

The Saint John Police Force said Wednesday they had obtained a Canada-wide arrest warrant for a 70-year-old man and a 44-year-old woman in the Oct. 7 theft at W. Smith and Co. Fine Jewellers.

The force did not give further details, but storeowner Wayne Smith said the couple were European and living in the Toronto area.

"The police have been right on to it, they've just been working diligently here," Smith said Wednesday.

Smith went public about the robbery at his store this month, and said he has since heard directly from stores and police officers from coast to coast about similar heists.

The thieves present themselves as a middle-aged couple arguing over how many carats to buy, and then switch real diamonds with fakes while salespeople are distracted.

The most recent reported robbery was at a store in Charlottetown, where police said the same couple that hit Saint John "managed to swap useless stones for two diamonds valued at approximately $20,000."

Smith said such thefts are not uncommon at jewelry stores, but they're usually kept quiet. He said he decided to speak out because his insurance deductible is so high it won't cover the loss, and because the video is so clear the culprits can be easily identified.

Smith said he now directly knows of a half-dozen thefts from Vancouver to the Maritimes, and thinks there are likely dozens more. He said more than $1 million in diamonds may have been stolen.

"It'll make me ecstatic when some of the jewellers get their goods back, and it may be a start of jewellers communicating across Canada more when they do have a robbery, so that we can narrow this down and maybe prevent something from happening in the future," Smith said.

"It's also a good awareness that all jewellery stores need to have up-to-date, sophisticated camera equipment."