Aristolochic Acid is a natural product of plants used in some weight loss supplements.
But the acid could be causing DNA to change in the liver, scientists have revealed.
Previous research also revealed that the remedy causes kidney and urinary tract cancers.
The scientists said that supplements containing the acid was easily available online, and it was important to educate the public about its danger to health.
“This is a follow up study for our 2013 paper, when our team made a breakthrough in understanding the cancer-promoting action of Aristolochic Acid in urinary tract cancer,” said Professor Teh, from the National Cancer Centre Singapore.
“Our new study establishes that Aristolochic Acid is also implicated in liver cancer.”
The researchers analysed the DNA of 98 people with liver cancer in Taiwan to find the link with the acid.
They found large amounts of the herb in more than 75 per cent of the patients.
Professor Hsieh Sen-Yung, a researcher working on the study said: “ Although we knew that there was exposure to the acid in Taiwan, we were very surprised to find such a high proportion of liver cancer sufferers had exposure to it.”
Analysing liver cancer from about 1,400 patients across the world they found herbal medicine, which used the acid, was being used globally.
Despite the acid being banned in Europe since 2001,the effects of the ban may take years to materialise, the scientists said. That meant it could also take years for rates of Aristolochic Acid-related cancers to fall.
In homeopathic remedies, different herbs are often bundled and sold together.
Some of those herb concoctions could contain Aristolochic Acid, the researchers said.
Remedies containing the acid are still widely available.
“Public education and awareness are very important for avoiding exposure,” said another researcher working on the study, Professor Alex Chang.