A British lawmaker on Wednesday released a trove of emails between Facebook and other tech companies that deal with how user data could be accessed through the social network's system.

The emails, which were part of a lawsuit app developer Six4Three brought against Facebook, were seized by British lawmakers in late November in connection with the U.K. Parliament's inquiry into disinformation and "fake news." The app developer is suing Facebook for cutting off its access to Facebook user data.

The lawmaker, Damian Collins, who is chairman of the committee tasked with investigating disinformation, tweeted that the documents "raise important questions about how Facebook treats users' data, their policies for working with app developers, and how they exercise their dominant position in the social media market."

"We don’t feel we have had straight answers from Facebook on these important issues, which is why we are releasing the documents," Collins added.

The emails, which run 250 pages, also include a summary of six "key issues" including the company's use of "white lists" to allow some companies to retain access to Facebook user data despite changes made to its system in 2014 and 2015.

Facebook's handling of user data in relation to connected apps became international news in March when it was revealed that a Cambridge Analytica, a political consultancy that worked with the Trump campaign, was able to gain access to user data on tens of millions of Facebook users through a personality quiz app.

The summary also highlights Facebook's tactics in competing with apps, in particular tracking their popularity through Onavo, which has been the subject of criticism for giving Facebook a way to monitor competitors, and strategically denying other apps access to user data.

"The files show evidence of Facebook taking aggressive positions against apps, with the consequence that denying them access to data led to the failure of that business," Collins wrote in the summary.

Facebook published a response the summary, outlining responses to each of Collins' summary points.

"The set of documents, by design, tells only one side of the story and omits important context," the company wrote in a blog post.

The trove of emails contains a variety of discussions about how the company dealt with other apps. In one exchange, Mark Zuckerberg, Facebook co-founder and chief executive, approves a move to cut off a new app from Twitter — Vine, a short-form video app that would find fleeting success — which used Facebook to help people find their friends on the app.

There are a ton of Facebook internal emails out now from parliament. https://t.co/DlSSlq9WfQ

The biggest reveal here isn’t the data privacy stuff— it’s how ruthless Facebook is as a competitor. pic.twitter.com/3QqlYRYDK6 — Sarah Frier (@sarahfrier) December 5, 2018

The documents could also have consequences for Facebook in the U.S., where it has also come under increasing scrutiny. Ashkan Soltani, former chief technologist for the Federal Trade Commission, pointed out on Twitter that some of the emails appeared to violate Facebook's previous agreement with the FTC. If Facebook is found to have violated its FTC deal, the company could face a sizable fine.

The emails also highlight how Zuckerberg was still working on Facebook's business model in 2012, when emails show he considered selling access to user data in return for ad spending — something that Facebook has recently clarified the company never did.

7) @FTC consent decree required that @Facebook get 1A) affirmative consent before the collection of covered info 4A) create a privacy program to address privacy risks



However, docs show lead of privacy program was actively working to evade user consent https://t.co/mcXhDnSg2i pic.twitter.com/Z3CEvsWE80 — ashkan soltani (@ashk4n) December 5, 2018

When asked for comment, a spokesperson for Facebook said in an email: “As we've said many times, the documents Six4Three gathered for their baseless case are only part of the story and are presented in a way that is very misleading without additional context. We stand by the platform changes we made in 2015 to stop a person from sharing their friends' data with developers.

"Like any business, we had many of internal conversations about the various ways we could build a sustainable business model for our platform. But the facts are clear: We've never sold people’s data.”

Later on Wednesday, Zuckerberg echoed that point in a Facebook post.

"We've focused on preventing abusive apps for years, and that was the main purpose of this major platform change starting in 2014," Zuckerberg said of closing off developer access to Facebook data. "In fact, this was the change required to prevent the situation with Cambridge Analytica. While we made this change several years ago, if we had only done it a year sooner we could have prevented that situation completely."

Zuckerberg ended his post by discussing press coverage of Facebook, which he has recently become more critical of.

"I understand there is a lot of scrutiny on how we run our systems," he wrote. "That's healthy given the vast number of people who use our services around the world, and it is right that we are constantly asked to explain what we do. But it's also important that the coverage of what we do — including the explanation of these internal documents — doesn't misrepresent our actions or motives. This was an important change to protect our community, and it achieved its goal."