Nasa leader Raila Odinga has reacted for the first time about the apocalyptic campaign against him in the 2017 election, saying it depicted him as the "devil incarnate".
The videos and the divisive campaign that reportedly started in 2013 has since been linked to the controversial British firm Cambridge Analytica and Harris Media.
Cambridge Analytica is said to have mined personal data from giant social media site Facebook to craft personalized messages to convince voters.
British TV station Channel 4 exposed the data firm bragging to its undercover reporter of having fixed the Kenyan elections for President Uhuru Kenyatta in both 2013 and 2017.
Mr Odinga now says he will sue both Facebook and Cambridge Analytica.
TO SUE OUTSIDE KENYA
"I am disappointed that Facebook agreed to cooperate in this clandestine enterprise. I have been very disappointed, and we are actually contemplating legal action against Facebook. . . We will do it outside Kenya with Kenyan lawyers and others from outside," he told Channel 4 News, calling for legislation to stop such further infringement in Kenya.
On whether he will also sue Cambridge Analytica, he answered in the affirmative, saying "Most certainly."
Mr Odinga, who was speaking for the first time about the allegations levelled against the British firm, which it has denied, said that the firm took advantage of the impressive internet penetration statistics in Kenya.
"The Real Raila Odinga in those videos was a very evil man. . . The devil incarnate," Mr Odinga told the British station in an interview aired on Monday night.
The 'Real Raila' videos which depicted Mr Odinga as violent, incapable of leading, and a man who should not be allowed to lead were made by Harris Media, a report by Privacy International said last year.
In the interview, Mr Odinga said Harris Media and Cambridge Analytical were no different.
"The net result of the work by Cambridge Analytica and Harris Media, which worked for the same client, is that this was a very negative campaign," he explained.
In the secret Channel 4 investigative video aired last week, the firm brags that it "rebranded the (Jubilee) Party twice, wrote their manifesto, done two rounds of 50,000-strong or so surveys, as well as writing all its speeches."
Its effect, Mr Odinga explained: "I think we were one of the first guinea pigs in this experiment. In 2013, we were new to this kind of thing, and we did not know how to deal with it. And then they came in 2016, and this time, they had perfected the art of manipulating data."
Cambridge Analytica has since suspended its chief executive Alexander Nix, whom they said did not, in the Channel 4 News video, depict the values the company stands for.
President Kenyatta's Jubilee Party has denied working with the firm in both its 2013 and 2017 campaigns. However, Jubilee Party vice-chairman David Murathe, without expounding, has said that the party had paid for "branding" in the 2017 presidential election from SCL, an affiliate of consultancy Cambridge Analytica.
Facebook, on the other hand, has apologised to its users, saying that the data was irregularly given to the firm by a second party, who had wanted to use it for academic purposes, without its consent.
Mr Odinga warned that if left unchecked, the campaign tactics taken by the British firm would kill democracy.
"The introduction of this system brought by Cambridge Analytica is a danger universally... if this development is allowed to succeed, then there is no point of having elections, because it will not be the will of the people. The people will be turned to robots," Mr Odinga said in the TV interview.