A collection of nearly 50 scientists has urged the London Science Museum to end three oil company partnerships, with the collective arguing the sponsorships are "undermining" the museum as a scientific institution.

Called Culture Unstained, the activist collective includes signatories such as broadcaster Chris Packham and writer Sir Jonathon Porritt, who are urging the Science Museum to drop deals with fossil fuel companies BP, Shell and Equinor.

Having obtained internal reports through Freedom of Information requests, the group says that the museum approved sponsorship deals with these companies despite being aware they are involved in alleged "corruption, pollution and links to human rights violations".

"To accept sponsorship from an industry that has worked to cast doubt on climate science undermines the scientific community’s clear message that climate change is real and urgent," said professor Naomi Oreskes, one of the 46 signatories.

"Science museums have a crucial role to play in furthering the public’s understanding of climate science. Partnerships like these risk damaging the public’s trust in scientific institutions while legitimising the anti-scientific activities of fossil fuel companies."

Equinor – a Norwegian company formerly known as Statoil – is currently a sponsor of the Science Museum's Wonderlab Gallery, while BP recently sponsored the museum's Enterprising Science research project. In 2014 Shell tried to influence part of an exhibition, according to a Guardian report and more recently it held its annual science-themed festival – Make The Future Live – at which the Science Museum participated. The letter was released to coincide with the festival.

"The Science Museum Group’s stance is that external sponsorship is not only necessary, it is a positive aspect of the way we work," said Science Museum Group director Ian Blatchford, speaking to the Museum Association's Museums Journal.

"While I acknowledge the passion of campaigners who would rather we turned our backs on a variety of legitimate business sectors, I strongly believe we are making the right decisions to secure the long-term future of the museum for the public good, a stance agreed by the board of trustees. Any partner that wishes to work with us has to accept that editorial control sits firmly with the museum."