Medication known as incretin mimetics could double the risk of developing pancreatic cancer, according to researchers.
The drug, which is more commonly known as GLP-1, regulates blood sugar and is used by doctors to treat people suffering from Type 2 diabetes.
But the drug also holds back appetite, the Daily Express reported.
Now, health insurance data revealed that people taking the medication is twice as likely to be admitted to hospital with pancreatic cancer as patients taking other types of diabetic drugs.
The investigation has been backed by findings from the US suggesting an increase in reports of pancreatic cancer in people taking the drug.
The research from the University of California found harmful changes to the digestive system of animals given GLP-1.
Eight organ donors who took the drugs were found to have small amounts of pre-cancerous lesions, while other donors given alternative medication had none.
The European Medicines Agency and the US Food and Drug Administration have launched a review of GLP-1 drugs and have said that more research needs to be done before regulators can declare them safe.
The findings have been published in the British Medical Journal.