Cambridge Analytica elaborated in a statement, saying that it had posed a series of "ludicrous hypothetical scenarios" to determine whether the client was someone they should engage with.
"I am aware how this looks, but it is simply not the case," Nix said in the statement. "I must emphatically state that Cambridge Analytica does not condone or engage in entrapment, bribes or so-called 'honeytraps', and nor does it use untrue material for any purpose. I deeply regret my role in the meeting and I have already apologised to staff. I should have recognised where the prospective client was taking our conversations and ended the relationship sooner."
For Cambridge Analytica, the Channel 4 News expose is only the latest headache for a firm once championed by conservatives - and boosted by US$15 million in funding from Republican mega-donor Robert Mercer, and his daughter, Rebekah.
It has ties to Steve Bannon, the former campaign adviser to Trump, whose campaign spent at least US$6 million on the firm's services during the 2016 presidential race. Cambridge Analytica previously aided Republican Senator Ted Cruz during the 2016 presidential primary.
According to the video posted by Channel 4 News, Nix appears to suggest the company could "send some girls around to the candidate's house." He later added that he favoured Ukranian women in particular: "They are very beautiful, I find that works very well."
The surreptitiously recorded video also appears to depict conversations involving Nix, Mark Turnbull, the managing director of Cambridge Analytica Political Global, and Alex Tayler, the chief data officer. The Channel 4 News team reportedly told the company officials they were meeting with a "fixer for a wealthy client hoping to get candidates elected in Sri Lanka."
The executives repeatedly appear to brag about their behind-the-scenes efforts to influence political outcomes in Mexico, Australia and Kenya, at one point teasing that they're beginning to work in China, too.
In one clip, Turnbull stresses the firm is not "in the business of fake news, we're not in the business of lying, making stuff up, and we're not in the business of entrapment. So we wouldn't send a pretty girl out to seduce a politician and then film them in their bedroom."
In a later conversation featuring Nix, however, the chief executive appears to float the idea that they could entrap candidates with potential bribes, "instantly having video evidence of corruption, putting it on the internet."
Nix later added, "Please don't pay too much attention to what I'm saying because I'm just giving you examples of what can be done, and what has been done."
In a number of the exchanges, Turnbull stresses the ability of Cambridge Analytica to play on people's "hopes and fears."
"You didn't know that was a fear until you saw something that just evoked that reaction from you," Turnbull appeared to say, "and our job is to get, is to drop the bucket further down the well than anybody else, to understand what are those really, deep-seated underlying fears, concerns."
In other clips, Turnbull describes links to former spies while also promising to be discreet, using "a different entity, with a different name, so that no record exists with our name attached to this at all."
Following the expose, Elizabeth Denham, Britain's Information Commissioner, told Channel 4 News that she was "shocked" and "deeply concerned."
Her office has been conducting a widespread probe, which started last year, into data analytics and political profiling.
She said that she would be applying for a warrant to access Cambridge Analytica's databases and servers to "understand how data was processed or deleted by Cambridge Analytica - there are a lot of conflicting stories about the data."
When asked if she was concerned about Facebook getting "ahead" of her office by sending in its own team to Cambridge Analytica's London offices, she said: "I think it's very important that we apply for the warrant and that we do the search on behalf of the public."
But without a warrant, her office was unable to send in its own team.
Channel 4 News, the flagship news programme of Channel 4, is a commercially-funded, publicly-owned broadcaster, which operates separately from the BBC.
