Seventeen-year-old Swedish climate activist Greta Thunberg responded Saturday to a widely-condemned sexually graphic illustration posted on Facebook.

"They are starting to get more and more desperate," Thunberg said in a message posted to her Twitter account. "This shows we are winning."

Thunberg's global campaign in favour of action to combat climate change has made her a target for criticism on social media.

Alberta's premier and two cabinet ministers were part of a chorus of condemnation levelled at a Red Deer oilfield company after the illustration surfaced.

The illustration, published Wednesday, shows a female figure — viewed from behind and apparently naked — with long, braided hair being pulled back by a pair of hands. The name "Greta" is written across her back, an apparent reference to Thunberg.

Directly below the image is the logo of the oilfield company X-Site Energy Services.

Thunberg drew criticism from supporters of the oil and gas sector when she made a series of appearances across Canada last year, which included a climate rally at the Alberta legislature.

The image, which CBC News has chosen not to republish, has been widely denounced on social media.

Alberta's minister for the status of women, Leela Aheer, called the graphic "completely deplorable, unacceptable and degrading."

"This is not what our province stands for," she wrote on Twitter. "Whoever is responsible should be ashamed and apologize immediately. I stand with Albertans against this horrendous image."

Premier Jason Kenney tweeted in response: "Thank you for denouncing this odious image and the message it sends."

On her Twitter account, Alberta Energy Minister Sonya Savage called the graphic "completely unacceptable" and echoed Aheer's call for an apology.

Visual is 'jarring'

X-Site general manager Doug Sparrow declined a request for an interview when contacted by CBC News.

In early February, X-Site said on Instagram it had named its high-efficiency heater The Greta. (x_site_energy/Instagram)

Sparrow did not return messages seeking comment from The Canadian Press, but told Calgary radio station CFFR he has received hundreds of complaints, though his company wasn't involved.

"It's not from X-Site or any employee," Sparrow told the radio station. "Someone has done this. That's all I know."

Michelle Narang of Rocky Mountain House, Alta., first posted the graphic on her Facebook page Wednesday evening. She said a friend who works in the oil and gas industry texted her a photo of the decal and told her an X-Site employee had been handing them out.

"The visual is jarring," said Narang, who has two teenage daughters. "It hurt on so many levels."

Narang said she was reluctant to share the image because she didn't want to give the energy sector another black eye.

"In Alberta, especially, we are fighting so hard for an industry that means so much to us, and to have that sort of sabotage from within — you can't do that."

Narang said she has been heartened by industry workers speaking out against the image. She said she called the RCMP to report the decal as child pornography.

RCMP Cpl. Ron Bumbry said officers were aware of the image and "will be following up."

On Friday, Red Deer RCMP said it had completed its investigation into the decal.

"In consultation with police officers whose expertise includes the sexual exploitation of children, Red Deer RCMP determined that the decal does not meet the elements of child pornography," RCMP said in a news release. "Nor does the decal depict a non-consensual act that would be a direct threat to the person."

Alberta RCMP do not believe the decal constitutes a criminal offence, police said.

A Red Deer graphic design company that has produced decals for X-Site in the past said it had nothing to do with the image.

"I thought it was disgusting," said Serina Roker, production manager for Velocity Graphics.

Comments on social media linking Velocity to the image prompted Roker to issue a statement, denying they produced it. She said the company will not work with X-Site in the future.

"False accusations like this can really damage a company," said Roker.

In early February, X-Site said on Instagram it had named its high-efficiency heater The Greta.