Cancer Research UK has begun drawing up its first cross-cutting ethical policy to determine how the charity invests in, works with and accepts donations from companies and corporations.
The move is designed to improve accountability within the charity.
Maxine Taylor, director of policy and communications at CRUK, said it was crucial that charities were transparent in their operations, and an ethical policy was one way of showing this.
CRUK is consulting internally and with other charities, and is considering using an external consultancy to examine how it should work with tobacco, pharmaceutical, food and mobile phone companies, among others.
"This is an issue for the voluntary sector as a whole, as it is for the corporate sector," said Taylor, who joined the charity recently from a pharmaceutical company.
"We get a lot of our funds from the public, so there's an expectation that we're clear about who we work with, why we work with them, whether they affect our reputation and what the implications of that are."
The charity already has a tobacco policy that prevents it from investing in and accepting donations from tobacco companies because of the cancer risks of smoking. It has monitoring systems in place to ensure it does not invest inadvertently in tobacco. Smoking on CRUK's premises is a sackable offence.
Taylor said developing the policy would be a challenge because the scientific evidence base is constantly changing, and because there were conflicting issues to consider when accepting donations.
"It depends what is meant by a 'donation'," she said. "We tend to take all approaches on a case-by-case basis. If a company's employees want to make us their charity of the year, that is different from a company seeking a product endorsement, whether for a pharmaceutical product or an unhealthy food product.
"The major consideration would be whether, by accepting a donation, it would compromise our reputation," she added.
Cancer Research UK is in the process of drawing up a policy that will determine how the charity works with and accepts donations from companies and corporations
The charity aims to improve its accountability and transparency
It already has a policy that prevents it from investing in and accepting donations from tobacco companies.