Cambridge University has accepted a multimillion-pound donation from Shell to fund a team researching oil extraction technology, even as it publicly positions itself as part of the transition to a sustainable future.

Shell has given £6m to fund the work of the university’s magnetic resonance research group amid a concerted campaign by students and staff to persuade the university to sever its links with extractive industries.

The university was praised earlier this year after its management agreed to provide fully costed plans setting out how it could divest multibillion-pound endowments from fossil fuel corporations. But critics have described the recent donation as a reversal.

The Shell donation was approved in March, but details of it were not included among official disclosures in July, when most donations from the last academic year were announced. Details have emerged days before a senior Shell executive is due to address senior university staff on whether Cambridge should continue to accept funding from fossil fuel companies.

Sinead Lynch, the chair of Shell UK, has been invited to join the panel at a policy-making workshop on Monday. Environmental campaigners at Cambridge have raised questions about potential links between the donation and the invitation.

A spokesperson for Cambridge Zero Carbon said the university had been “hijacked” by the fossil fuel industry, which was already earning hundreds of millions off Cambridge research breakthroughs.

“Fossil fuel executives should be in court for their crimes against humanity, not helping determine the policy of leading public research institutions,” the spokesperson said.

The latest funding from Shell was described by the university as “the final gift in a commitment [dating] back to 2014” to fund the magnetic resonance research group.

“The main focus of Prof [Lynn] Gladden’s proposed research related to the gift is on supporting the transition to a zero-carbon economy by improving chemical reactions in fuel cells, electrolysers and making chemical processes for industrial use more sustainable,” a spokesperson said.

However, the Guardian understands that hydrocarbon recovery is also among the areas to be researched with the money. On Gladden’s own page on the Cambridge university website she listed “oil recovery” among her research interests. A recent student-led investigation found she was named as the lead inventor on two oil exploration technologies, most recently in January.

“Magnetic resonance has long been used in the oil drilling sector as a method for assessing the fluid composition within oil-bearing rocks,” her page on the Cambridge website says. “For example, we can use [it] to explore how the treatment fluid moves and deposits within the rock so that we can optimise its properties to maximise the oil recovery from the rock, and water retention within the rock, during an extraction process.”

Despite the efforts of campaigners, Cambridge in 2017 rejected proposals to fully divest from fossil fuels. At the beginning of the year it was revealed that as university management considered the decision, the institution kept secret offers of multimillion-pound donations from BP and the mining company BHP. Cambridge has denied the money had any bearing on its decision.

A spokesperson for the university said that as it accepted the latest funding from Shell, it had called for a “set of principles” by which to assess future donations from companies involved in fossil fuel extraction and other controversial industries.

It was on this basis that it had invited Lynch, alongside others, to speak at the university on Monday. “The university has invited, among others, the student society Cambridge Zero Carbon, Friends of the Earth, climate scientists, Shell, council members and members of the [university’s committee on benefactions and external and legal affairs] to the meeting,” it said.

After publication, a university spokesperson said the gift from Shell had not been announced because the paperwork had yet to be completed.

• This article was amended on 7 November 2019 to add further comment from the university spokesperson.