A pigeon wearing a tiny empty backpack has been captured in a federal prison in British Columbia, which an official says is likely a way for inmates to smuggle drugs.

John Randle, the Pacific regional president at the Union of Canadian Correctional Officers, told the Canadian Press that the pigeon was found inside the Matsqui prison on Feb. 27. The backpack it carried was made of blue jeans and bedsheets—materials easily available to inmates, he said.

This is the second pigeon found carrying a backpack at the Fraser Valley prison in recent months. In January, another pigeon was caught in a fenced yard where inmates regularly spend leisure time, carrying a cargo of 30 grams of crystal meth.

Randle previously said, after the first incident, that the government has been preoccupied with the increased use of drone smugglers, and that he hasn’t heard of another live pigeon being used for trafficking drugs in the past 13 years.

“We’ve been focusing so much on drone interdiction … now we have to look at I guess pigeons again,” Randle said.

Following the latest incident, Randle said there is an elementary school close to the federal security facility, which raises concerns about pigeons used for trafficking drugs to inmates landing in the wrong place, The Canadian Press reported.

“We are working with the local police because we control what happens inside the fence, but this one here has the potential to have an impact outside of the fence, on the general public as well,” he said.

Randle noted that officers are pushing the federal agency Correctional Services of Canada to “step in” and “start taking things seriously” because it’s getting more frequent for people to seek different ways to smuggle drugs into the prison.

Police in Abbotsford said they’re investigating the latest pigeon pack.

The Canadian Press contributed to this report.