Four of the world's biggest tech platforms have working partnerships with a left-wing nonprofit that has a track record of inaccuracies and routinely labels conservative organizations as "hate groups."

Facebook, Amazon, Google and Twitter all work with or consult the Southern Poverty Law Center (SPLC) in policing their platforms for "hate speech" or "hate groups," a Daily Caller News Foundation investigation found.

The SPLC is on a list of "external experts and organizations" that Facebook works with "to inform our hate speech policies," Facebook spokeswoman Ruchika Budhraja told TheDCNF in an interview.

Facebook consults the outside organizations when developing changes to hate speech policies, Budhraja said, noting that Facebook representatives will typically hold between one and three meetings with the groups.

Citing privacy concerns, the Facebook spokeswoman declined to name all the outside groups working with Facebook, but confirmed the SPLC's participation.

Budhraja emphasized that Facebook's definition of "hate group" is distinct from the SPLC's definition and said that Facebook consults with groups across the political spectrum.

The SPLC accused Facebook in a May 8 article of not doing enough to censor "anti-Muslim hate" on the platform. That article did not disclose the SPLC's working partnership with Facebook.

"We have our own process and our processes are different and I think that's why we get the criticism [from the SPLC], because organizations that are hate organizations by their standards don't match ours," Budhraja said.

"That doesn't mean that we don't have a process in place, and that definitely doesn't mean we want the platform to be a place for hate but we aren't going to map to the SPLC's list or process," she said.

Of the four companies, Amazon gives the SPLC the most direct authority over its platform, TheDCNF found.

While Facebook emphasizes its independence from the SPLC, Amazon does the opposite: Jeff Bezos' company grants the SPLC broad policing power over the Amazon Smile charitable program, while claiming to remain unbiased.

"We remove organizations that the SPLC deems as ineligible," an Amazon spokeswoman told TheDCNF.