Cancer center officials said that they acted properly in approving the deal with Paige.AI and that if successful, the venture could change the future of cancer diagnosis. “This is an incredibly expensive undertaking — it needs a lot of money,” Dr. Gregory Raskin, the hospital’s vice president of technology development, said in an interview. “We feel this is a really valuable and important technology to get developed.”

Officials said that some board members invested only after early efforts to generate interest from outside companies and investors had failed. But they acknowledged that they did not seek an independent valuation of the tissue archive, nor did they put the proposal out for competitive bidding before licensing it to a single company. In exchange for sharing its voluminous database, Memorial Sloan Kettering received ownership shares amounting to about nine percent in the company.

Image Thomas Fuchs, head of the MSK computational pathology lab and a co-founder of Paige.AI.

“It just seems awfully coincidental that the individuals involved happen to be people in control and influence of that asset, and they ended up with an exclusive use of it,” said Marcus S. Owens, a Washington lawyer who ran the Internal Revenue Service division that oversees tax-exempt organizations. “It seems to create a cascading series of conflicts for the operation of Sloan Kettering.”

The decision to license images of the patients’ tissue slides to a for-profit company also highlights the broader debate over the use of personal medical data, ranging from genetic information to, in this case, images of a person’s cells, for research and commercial purposes.

After ProPublica and The Times began asking questions about the arrangement, one of the founders — Dr. David Klimstra, the chairman of the pathology department — said he would divest his ownership stake.

Dr. Klimstra and another co-founder, Dr. Thomas Fuchs, the head of the computational pathology laboratory, pursued the idea for Paige.AI in 2015, hospital officials said. Dr. Fuchs had previously worked for NASA developing algorithms that would teach the Mars rovers to navigate terrain, and has said some of the same algorithms can differentiate cancerous tumors from benign ones. In a statement, he called the AI start-up the culmination of his “life’s work.”