Toronto police have launched an investigation after an image allegedly showing Blue Jays’ Roberto Osuna in a holding cell was leaked to a news outlet.

The photo, which appeared online Wednesday, showed a man dressed in black, sitting in a police holding cell with his back against a wall and his legs on a rectangular bench.

When a Twitter user criticized the photo leak, Toronto Police responded: “There is a Toronto Police Service Professional Standards investigation commenced relating to the Osuna photo.”

The 23-year-old closer was arrested sometime Tuesday morning and charged with one count of assault.

He was released the same day but is due to face the charge in court at Old City Hall on June 18.

Toronto police Chief Mark Saunders says he's "not proud" of the situation.

"As an organization I do take our roles and responsibilities seriously. I can tell you our professional standards is actively investigating and looking into it. I am looking for opportunities to prevent this type of behaviour," he said.

“I don't have a great answer for this and it's not something I'm very proud of.”

Saunders said the investigation is in the early stages and would not speculate on the repercussions, if any.

"Rest assured that professional standards will do everything and anything that they can do to locate where this came from and as an organization we'll take a step back and look at what steps we need to do," he said.

Police have declined to provide further details about the case.

Shortly after the news broke, the Major League Baseball (MLB) announced that Osuna had been placed on administrative leave.

The decision was made “in accordance with the Joint MLB-MLBPA Domestic Violence Policy,” the MLB wrote in a statement.

The policy was implemented in 2015 and allows for a player believed to be involved in a domestic-related incident to be placed on leave, regardless of whether it is brought before the courts.

An administrative leave is not considered discipline by the MLB. The seven-day absence allows the league to investigate before going any further, if at all.

The Blue Jays released a statement later Tuesday, saying they “fully support” the decision to place Osuna on administrative leave.

“We are taking the matter extremely seriously, as the type of conduct associated with this incident is not reflective of our values as an organization,” the statement reads in part. “As this remains an ongoing investigation by Toronto Police, the Club will not comment further on this matter.”

When asked about the photo before Wednesday night's game against the Seattle Mariners, Jays manager John Gibbons said he hasn't seen the photo.

"I really don't care about that," he said. "From here on out they'll do their investigations. I don't really want to comment on that."

The leak follows a similar incident last month where an image of the suspect in the Toronto van attack was released by a newspaper.

The photo appeared to show Alek Minassian being held at the Toronto South Detention Centre shortly after the deadly April 23 incident.

Ontario’s Ministry of Corrections and Community Safety has said it is investigating that leak.

With files from the Canadian Press