According to Swedish tabloid Expressen, WikiLeaks tasked a team of activists to secretly investigate the newspaper's editor, Thomas Mattson, as well as Ulrika Knutson, the head of Sweden's National Press Club (Publicistklubben).
"They have ascertained that at least three reporters who work for two different media houses are involved in the conspiracy," WikiLeaks sources told Expressen.
"They have surreptitiously photographed people suspected of being involved in the conspiracy against Assange, they have also accessed information from public records and gained access to secret material from government databases."
Expressen is the Swedish newspaper which first reported in August 2010 that Assange had been accused of sex crimes and that a warrant had been issued for his arrest.
WikiLeaks and Assange have long claimed that the sex crimes accusations are part of a larger conspiracy against him in response to the websites release of thousands of sensitive US diplomatic cables.
According to Expressen's sources, WikiLeaks leaders believe Swedish journalists, politicians, and government officials are involved in the alleged conspiracy and have been working on measures to "reveal the conspiracy" in order to prevent Assange from eventually being extradited to the US.
When told WikiLeaks had been gathering information on her, National Press Club head Knutson told Expressen "I don't know whether to laugh or cry".
According to Expressen editor Mattson, "WikiLeaks has attacked Expressen" ever since the paper's scoop regarding the sex crime allegations against Assange.
"I consider the investigation of me and other Swedish journalists as an attempt to find something that can be used to question relevant news coverage about Wikileaks," he said.
Writing about the matter on his official blog, Mattson emphasized the importance of distinguishing the work of WikiLeaks from Assange.
"WikiLeaks is important. But Assange is irresponsible when he criticizes independent media like this," wrote Matsson.
"The attempt to map Swedish publishers like Ulrika Knutson and me in the hope of being able to expose a conspiracy in which journalists accept payment to write negatively about WikiLeaks unfortunately shows a complete lack of knowledge about how independent news gathering works."
WikiLeaks spokesperson Kristinn Hrafnsson denied the website had engaged in any sort of probe of Mattson or other Swedish journalists.
"No, I'm not aware of any investigation taken place," she told Expressen.