TV4 personnel have been threatened following their investigation into the Sweden Democrats' (SD) troll accounts.

Reporters received threats after revealing that SD's communications department runs multiple anonymous social media accounts spreading misleading information.

As a result, TV4 has increased security, advising staff not to display their workplace affiliations publicly.

TV4 News and Kalla fakta editor-in-chief Fredrick Malmberg confirmed that police reports have been filed regarding these threats.

The investigation uncovered at least 23 anonymous accounts managed by SD's communications team.