The work of one of the most famous and influential British psychologists of all time, Hans Eysenck, is under a cloud following an investigation by King’s College London, which has found 26 of his published papers “unsafe”.

King’s says the results and conclusions of the papers “were not considered scientifically rigorous” by its committee of inquiry. Prof Sir Robert Lechler, the provost at King’s, has contacted the editors of the 11 journals where the papers appeared, recommending they should be retracted.

Eysenck, who died in 1997, published prolifically and wrote many well-known books, holding controversial views on a number of subjects, including race and IQ. The investigation centred on research that claimed personality played a bigger part in people’s chances of dying from cancer or heart disease than smoking.

There has been criticism of Eysenck’s work for decades by scientists, but his papers have continued to be cited and his ideas adopted. His work on personality and disease was carried out in collaboration with a German researcher, Ronald Grossarth-Maticek, who studied cohorts of people in Crvenka, in what was then Yugoslavia, and Heidelberg, between the 1960s and 1980s.

Prof Anthony Pelosi, consultant psychiatrist at the Priory Hospital, Glasgow, whose own investigation prompted the inquiry by King’s, said their work “led to what must be the most astonishing series of findings ever published in the peer-reviewed scientific literature, with effect sizes that have never otherwise been encountered in biomedical research”.

It took Pelosi three years to get his concerns published, after the journal Eysenck founded, Personality and Individual Differences, rejected the paper it had invited Pelosi to write. It was finally published in February in the Journal of Health Psychology, whose editor, David Marks, called for the establishment of a national research integrity ombudsperson to investigate allegations. The findings were backed by Richard Smith, the former editor of the BMJ, which had published criticisms of Eysenck as long ago as 1992.

“This research programme has led to one of the worst scientific scandals of all time,” wrote Pelosi.

Among more than 3,000 people in the studies, Eysenck and his colleague claimed people with a “cancer-prone” personality were 121 times more likely to die of the disease than those without, and people with “heart-disease prone” personalities 27 times more likely.

Cancer-prone personalities were described as generally passive in the face of stress from outside. Those who were heart disease-prone were unable to leave an unsatisfactory situation alone, which made them increasingly aggressive and hostile. A healthy personality was autonomous, with a positive outlook.

Eysenck and Grossarth-Maticek apparently even had a “cure” for cancer. In one study, they gave 600 “cancer-prone” individuals a leaflet on how to be more “autonomous” and take control of their destiny. It contained such advice as: “Your aim should always be to produce conditions which make it possible for you to lead a happy and contented life.”

It appeared to deliver miracles. Over 13 years, the 600 people randomly assigned to bibliotherapy, as it was called, had all-cause mortality of 32%, compared with 82% of 600 people not fortunate enough to receive a leaflet.

“I honestly believe, having read it so carefully and tried to find alternative interpretations, that this is fraudulent work,” said Pelosi, who is concerned Eysenck’s ideas still have a following.

“His acolytes always bragged he was the most cited psychologist of all time,” Pelosi added. “In the social sciences citation index, he was number three. Number two was Freud. Number one was Karl Marx. He was hugely prolific, widely cited and very influential.”

Documents from litigation in the US show that Eysenck’s theories on personality as a stronger cause of lung cancer than smoking brought him research funding from the tobacco companies. In 1991, he published a book called Smoking, Personality and Stress, re-issued as recently as 2012, in which he claims that “while smoking is a risk factor for cancer and CHD (coronary heart disease), its effects have been exaggerated”.

Pelosi says psychological issues, such as depression or anxiety, may play some part in physical illness. “I kind of think there is something in it and it is a worthy area of study, but Eysenck undermines it all by his ridiculous claims,” he said.

The motivation of Grossarth-Maticek, who is still alive and has been contacted for comment, “seems to have arisen from a quasi-religious belief that he can prevent cancer and delay death from terminal metastatic disease”, wrote Pelosi in his paper. “Many fringe medical practitioners hold the same conviction. Unlike them, Grossarth-Maticek tried to prove his beliefs, but with no epidemiological training and, in my opinion, serious shortcomings in his scientific and clinical understanding.

“Grossarth-Maticek had the misfortune to become a protégé of the most influential psychologist of his generation, who needed data to support his theories on the psychogenic causes of cancer.”