A new undercover video from a group of conservative investigative journalists appears to show Twitter staff and former employees talking about how they censor content they disagree with - and without the user ever knowing.

James O'Keefe, Project Veritas founder, posted a video showing an undercover reporter speaking to Abhinov Vadrevu, a former Twitter software engineer, at a San Francisco restaurant on January 3.

There, he discussed a technique referred to as 'shadow banning', which means that users' content is quietly blocked without them ever knowing about it. Their tweets would still appear to their followers, but it wouldn't appear in search results or anywhere else on Twitter.

A new undercover video from conservative investigative journalists Project Veritas appears to show Twitter staff talking about how they censor content they don't like

James O'Keefe, (pictured) Project Veritas, has posted a series of videos of undercover reporters speaking to Twitter staff and former engineers

'One strategy is to shadow ban so you have ultimate control. The idea of a shadow ban is that you ban someone but they don't know they've been banned, because they keep posting and no one sees their content.

'So they just think that no one is engaging with their content, when in reality, no one is seeing it.'

The tool was created to weed out fake bots and scammers but could be open to abuse.

Vadrevu admitted it was 'risky' because if people figure out they've been shadow banned they would be furious.

He added that he wasn't sure 'if Twitter does this any more.'

Olinda Hassan, a policy manager for Twitter's Trust and Safety team, was also filmed at a Twitter holiday party on December 15, talking about how the social network was developing an automated system for 'down ranking' 'shi**y people'.

Olinda Hassan, a policy manager for Twitter's Trust and Safety team, was filmed talking about development of a system for 'down ranking' 'shi**y people'

Ex-Twitter content review agent Mo Norai revealed last year that Twitter's alleged left-leaning staff meant that conservative and pro-Trump content was subject to far harsher scrutiny than liberal posts

Another Twitter engineer claimed that staff already have tools to censor pro-Trump or conservative content.

But it doesn't stop there. One Twitter engineer appeared to suggest that the social network was trying to 'ban, like, a way of talking.' Anyone found to be aggressive or negative 'will just vanish.'

'Every single conversation is going to be rated by a machine and the machine is going to say whether or not it's a positive thing or a negative thing,' Twitter software engineer Steven Pierre was filmed on December 8 saying as he discussed the development of an automated censure system.

'And whether it's positive or negative doesn't (inaudible), it's more like if somebody's being aggressive or not. Right? Somebody's just cursing at somebody, whatever, whatever. They may have point, but it will just vanish… It's not going to ban the mindset, it's going to ban, like, a way of talking.'

Ex-Twitter content review agent Mo Norai revealed last year that Twitter's alleged left-leaning staff meant that conservative and pro-Trump content was subject to far harsher scrutiny than liberal posts.

He added that such decisions on content were never written down 'but behind closed doors are lots of rules.'

'A lot of unwritten rules, and being that we're in San Francisco, we're in California, very liberal, a very blue state,' he explained to the undercover reporter on May 16, 2017. 'You had to be… I mean as a company you can't really say it because it would make you look bad, but behind closed doors are lots of rules.'

'There was, I would say… Twitter was probably about 90% Anti-Trump, maybe 99% Anti-Trump.'

Vadrevu admitted it was 'risky' because if people figure out they've been shadow banned they would be furious

Another Project Veritas reporter tracked down Pranay Singh, a direct messaging engineer at Twitter, at a San Francisco bar on January 5.

He explained, while dancing, how shadow banning algorithms can work, and how the majority of users who are targeted are Republicans.

'Yeah you look for Trump, or America, and you have like five thousand keywords to describe a redneck. Then you look and parse all the messages, all the pictures, and then you look for stuff that matches that stuff.'

Another investigation by Project Veritas also hinted at Twitter's liberal bias after Twitter senior network security engineer Clay Haynes told an undercover reporter Twitter is 'more than happy to help the Department of Justice in their little investigation' by providing them with 'every single tweet that [Trump] has posted, even the ones he's deleted. Any direct messages, any mentions.'

Haynes described Trump as 'dangerous' and 'a terrible human being and I want to get rid of him.'

In another meeting, at Morton's Steakhouse in San Francisco on January 7, Haynes said that Twitter has the ability to disclose 'every single message, every single tweet, whatever you log into, what profile pictures you upload.'

However, when O'Keefe - wearing a disguise - suggests that Haynes could look through Donald Trump and his son's messages to 'see what's in there,' Haynes made clear that Twitter would only do so as part of a legal process.

Another Twitter engineer claimed that staff already have tools to censor pro-Trump or conservative content

'There's a reason why we have a subpoena process'—meaning Twitter would only access that information if requested by law enforcement as part of an investigation after obtaining a subpoena,' he said.

A spokesperson for Twitter told International Business Times after the Haynes video

'The individual depicted in this video was speaking in a personal capacity and does not represent or speak for Twitter. Twitter only responds to valid legal requests, and does not share any user information with law enforcement without such a request.'

'We deplore the deceptive and underhanded tactics by which this footage was obtained and selectively edited to fit a pre-determined narrative,' Twitter's spokesperson said. 'Twitter is committed to enforcing our rules without bias and empowering every voice on our platform, in accordance with the Twitter Rules.'

DailyMail.com has reached out for comment on shadow banning.

O'Keefe has just completed a book about this series of undercover videos entitled 'MERICAN PRAVDA: My fight for Truth in the Era of Fake News, which is released on January 16.