The three, aboard AIR1, were on routine patrol when they inadvertently activated the system.
"As a result, the flight crew's conversation was publicly broadcast [and] some content of the conversation was inappropriate," stated a press release from the WPS.
"The involved members were not able to hear the public address system from within the aircraft. They became aware their conversation had been broadcast and immediately turned the system off."
Parts of the coarse conversation, which at one point touched on oral sex, were quickly posted to Twitter, and then spread across social media.
The tweets started about 10 p.m. local time, and caused #whoops and #speakerphone to trend in the Winnipeg area.
"The Winnipeg Police Service, the Flight Operations Unit, and the involved members sincerely apologize to all members of the public, especially those who overheard the broadcast," the WPS release said, adding the incident is being reviewed and the outcome "will be determined at a later time."
One of the first people to tweet about overhearing the remarks, Natanielle Felicitas, told CBC News Tuesday morning that she was enjoying a nice evening in her backyard with friends when the extra voices came from the sky.
"We paused to listen and were shocked by what we heard. It was a hilarious and inappropriate human blooper moment," she wrote in an email. "I rarely tweet, but this moment seemed too bizarre not to share."
Jacob Serebrin was walking with a friend near the Manitoba Legislature when they heard loud voices coming from above.
"We look up and there it is passing over and the two men in the helicopter were having a conversation, and we could hear part of it — some swears and some references to money," he said, adding he did not hear a specific reference to fellatio.
"Everyone does have private conversations in the workplace," Serebrin said. "But you know, there's certain things that are inappropriate for any workplace."