Facebook staff discussed charging companies for access to user data, before ultimately deciding against such a policy, according to reports.

The internal discussions were revealed due to improperly redacted court documents, released as part of Facebook’s lawsuit against American software developer Six4Three last year. According to Ars Technica and the Wall Street Journal, an 18-page court filing contains three pages that were supposed to be blacked out because they contain “sensitive discussion of Facebook’s internal strategic analysis of third-party applications”, Facebook said in other court filings.

But while the sensitive discussions were masked with a black bar, the underlying text was not removed from digital versions of the documents, allowing it to be uncovered.

That text reportedly shows Facebook staff discussing how to use access to user data to extract higher advertising spend from major clients, in emails dating from 2012 and 2013. The conversations occurred at roughly the time that Facebook decided to change the way third-party developers could access user data, which had the effect of closing the hole through which Cambridge Analytica partner GSR had managed to extract the personal information of millions of Facebook users.

In the filings, the Wall Street Journal reports, one employee proposes blocking access “in one go to all apps that don’t spend … at least $250k a year to maintain access to the data”.

Elsewhere, the filings suggest that Facebook offered to extend the length of time Tinder could continue using the old, more permissive terms of access in exchange for a licence for the dating company’s trademark on the term “Moments”.

There is no suggestion that Facebook acted on the proposals, and the company has always maintained that it tightened the restrictions on what could be done with its public access for privacy and security reasons.

The filings are drawn from a set of Facebook emails obtained by Six4Three in the discovery portion of its lawsuit against the social network, subsequently sealed by the Californian court. On Sunday, however, the UK parliament seized copies of the emails from Six4Three’s chief executive, and quoted from them during its grilling of a Facebook executive on Tuesday.

During the hearings, Labour’s Clive Effort asked whether “apps were shut down on the basis that they could not pay a large sum of money for mobile advertising”, and whether apps were “whitelisted” based on their advertising spend. Richard Allan, Facebook’s head of public policy in Europe, said no to both.

In a statement, Facebook’s director of developer platforms and programs, Konstantinos Papamiltiadis, told the Guardian: “As we’ve said many times, the documents Six4Three gathered for this baseless case are only part of the story and are presented in a way that is very misleading without additional context.” Facebook declined a request to provide the Guardian with the emails in their additional context, saying: “Evidence has been sealed by a California court so we are not able to disprove every false accusation.”

Papamiltiadis added: “That said, we stand by the platform changes we made in 2015 to stop a person from sharing their friends’ data with developers. Any short-term extensions granted during this platform transition were to prevent the changes from breaking user experience.

“To be clear, Facebook has never sold anyone’s data. Our APIs have always been free of charge and we have never required developers to pay for using them, either directly or by buying advertising.”