Footage of the attack was live streamed on Facebook by the gunman, who at one point can be heard saying: "Remember lads, subscribe to PewDiePie."
STOCKHOLM: YouTube's most-watched blogger PewDiePie said he was "sickened" after hearing that the gunman behind Friday's New Zealand mosque massacre had promoted his videos before opening fire.
Forty-nine people were killed and dozens more wounded in shootings at two mosques in Christchurch, in an attack which sparked global outrage.
Footage of the attack was live streamed on Facebook by the gunman, who at one point can be heard saying: "Remember lads, subscribe to PewDiePie."
The shooter, who is believed to be a 28-year-old Australian, has been arrested and charged with murder.
"Just heard news of the devastating reports from New Zealand Christchurch. I feel absolutely sickened having my name uttered by this person," tweeted PewDiePie, a 29-year-old Swede whose real name is Felix Kjellberg.
"My heart and thoughts go out to the victims, families and everyone affected by this tragedy."
The gunman, who was armed with semi-automatic weapons, had posted a hate-filled "manifesto" online before the carnage suggesting he was inspired by neo-Nazi ideology.
The Swedish blogger is known for posting humorous clips and playing livestreamed video games for his nearly 90 million followers on YouTube, making him the site's most watched blogger.