Victims injured during the bloody Las Vegas massacre earlier this month are now dealing with the additional stress of harassment by online conspiracy theorists.

One victim, Braden Matejka, told CTV Vancouver that his social media has been flooded with comments from people who claim the shooting by a lone gunman that killed 58 people was a hoax.

A bullet grazed the back of Matejka’s head when he and his girlfriend were trying to escape the chaos at the Route 91 Harvest country music festival on Oct. 1.

“It literally felt like being hit with a sledgehammer or baseball bat in the head,” he said, adding that he’s still in a lot of pain and can’t really move his head.

Despite the physical evidence of his injuries, online trolls have accused the B.C. mechanic of lying and being a paid actor.

“You’re a lying piece of s*** and I hope someone truly shoots you in the head,” wrote a poster on one of Matejka’s social media pages.

“Your soul is disgusting and dark,” wrote another.

The online abuse was so overwhelming that Matejka deleted all of his social media accounts.

Sheldon Mack, a 21-year-old man who was shot twice during the massacre, has also received negative remarks on his social media accounts.

“Sheldon has been also targeted online by someone who claims the shooting did not occur, and that he and others affected are actors participating in a hoax,” Mack’s father told CTV Vancouver. “We think it’s unfortunate that anyone without actual knowledge of the incident and its aftermath would choose to perpetrate such information.”

Mainland Medical Clinic psychologist Jodi Samra says online trolls who continue to spread these falsehoods are further harming the victims.

“What it really does is re-traumatize victims,” she said. "It's so horrific on so many levels. Here's people who are dealing with a whole host of emotional reactions – post traumatic stress, depression, anxiety, fear – their whole lives have been turned upside down. And then to have people on the outside that are making these ridiculous, outlandish, mean, hurtful statements, it's terrible."

Labelling victims of tragedies, particularly those injured in gun violence in the U.S., as so-called "crisis actors" isn’t a new phenomenon. Conspiracy theorists infamously attacked the grieving parents of children who were slaughtered in the Sandy Hook Elementary School shooting in Newtown, Connecticut in 2012.

Some argue that the shootings are faked as a way to sway public opinion in favour of gun control regulations.

Samra added that as unbelievable as their claims may seem to outsiders, there are plenty of people who truly believe them thanks to online groups that reaffirm their belief without offering contrary evidence.

“When we have groups, like conspiracy theorists groups, it’s amazing the power they have over having people start to believe something that’s completely false and may seem outlandish to us from the outside,” she said. "There is this belief now if something's on the internet that there's truth behind it."

With files from CTV Vancouver’s Shannon Paterson