The British government’s recently-departed shale gas commissioner admitted to routinely deleting correspondence and throwing away notes from meetings with fracking companies in a move that may have violated transparency requirements.

In response to an Unearthed freedom of information request sent earlier this year, Natascha Engel – who resigned this weekend after just 6 months in the role – said: “I tend to deal with everything on the day and delete what has been done to avoid any huge build-ups or risk of duplication.

“The same is true of the few notes I take in meetings which I review in the evenings, action and throw away.”

The failure to take notes and systematic destruction of information in this manner could be in breach of the Environmental Information Regulations 2004 (EIR).

The original request was for all email communications with the UK’s two leading fracking firms: INEOS – for which Engel has previously done paid work – and the Lancashire-based operator Cuadrilla.

Unearthed initially wrote to the Department for Business, Energy and Industrial Strategy (BEIS), which employs Engel for a fee of £500 a day, for the information but were told to apply directly to Engel herself who was described as “separate from BEIS.”

Following Engel’s response, Unearthed has requested an internal review of the handling of the request.

However it is not clear if the review will continue to be processed following Engel’s exit and, if so, who will conduct it, as Engel carried out the initial response and guidance from the Information Commissioner’s Office states that review of this nature should be “carried out by someone senior to the person who dealt with the original request” or, if that is not possible, “someone trained in, and who understands, the Environmental Information Regulations.”

Though Engel did provide a handful of emails in response to the request, there were no communications covering October 5, when she first entered the role, and December 30.

In her resignation letter to business secretary Greg Clark, Engel decried the government’s refusal to review the seismic activity standards that have made drilling incredibly difficult to carry out.

She wrote:“a perfectly viable and exciting new industry that could help meet our carbon reduction targets, make us energy secure and provide jobs in parts of the country that really need them is in danger of withering on the vine” unless the government reviews its rules on drilling-induced tremors.

Engel told the newspaper City AM the Unearthed investigation had “absolutely no bearing” on her decision to resign, and said: “I have not routinely destroyed my correspondence, what I’ve done is answered correspondence and deleted anything that I don’t need in order not to have an inbox that’s very full.”