According to tests carried out by the Paris-based National Institute of Consumption, more than half of leading colas contain traces of alcohol, Daily Mail reported on Wednesday.
These include the brand leaders Coca-Cola and Pepsi Cola, while it is mainly only cheap supermarket versions of the drink which are alcohol-free.
"60 Million Consumers", the French magazine, published the results of the tests in its latest issue.
The tests suggest that the alcohol levels are as low as 10 mg in every litre, and this works out at around 0.001 per cent alcohol.
But the figures will still be enough to upset the thousands of Muslims who regularly drink Cola because their religion forbids them from drinking alcohol, the daily said.