Bloomberg has reported there was a "direct collaboration" between employees of Facebook and Google and conservative non-profit Secure America Now and ad firm Harris Media.
Facebook also also reportedly worked with a Germany's far-right Alternative for Germany party, which is also a Harris Media client, to target voters with anti-immigration ads during this year’s election.
During the US presidential campaign one ad was a mock tourism film entitled "Book your trip to the Islamic State of France".
The ads reportedly ran in Nevada and North Carolina in the final weeks of the election.
Sources told Bloomberg that sales teams at Facebook and Google worked closely with Secure America Now to improve its multi-million dollar ad campaigns.
Bloomberg reports Google eventually pulled some of ads after they violated its policies, whereas Facebook went as far as using Secure America Now’s ads to A/B test at scale a new video format.