A charity events manager has been jailed for more than four years for defrauding almost £87,000 from the organisation.
Patricia Robertshaw, 42, who worked at Yorkshire Cancer Research in Harrogate, North Yorkshire, pretended she had cancer.
She invented fictitious hospital, chemotherapy and radiotherapy appointments and took extended periods of leave, claiming to be recovering from life-saving surgery.
Detective Constable Shane Martin, who led the case for North Yorkshire Police, said: "This is the most abhorrent fraud case I have investigated in 25 years of being a police officer.
"It’s absolutely incomprehensible that anyone could lie about having such a serious illness.
"Everything about the way Robertshaw conducted herself during this fraud is astonishingly unethical.
"It was a callous and calculated crime to try to trick her former employer, a charity that works for the good of real cancer patients and uses donations made in good faith to fund life-changing services and research."
Robertshaw, of Barrowford in Lancashire, had pleaded guilty to fraud by false representation and forging certificates at a previous hearing at York Crown Court in January.
She was sentenced to four years and five months yesterday for four fraud counts, including £86,833 against the charity, and one count of forgery.
The court heard that Robertshaw lied about her qualifications, produced false certificates to get jobs and submitted fake sick notes that were eventually detected by the charity.
In a previous job at a university she forged leadership qualifications for 55 students for work they completed under her guidance.
When the charity realised something was amiss, North Yorkshire Police began a major fraud operation.
Kathryn Scott, chief executive of Yorkshire Cancer Research, said in a statement: "It’s a very sad situation. We took action as soon as possible and as a charity we continue to focus on saving lives."
The charity, which generated income of £11m in the financial year ending 31 March 2018, declined to answer further questions other than to say "we have made changes" when asked what action it had taken to prevent a repeat.