Professor Simon Chapman of the University of Sydney refers to a recent Dutch research, saying that cigarette may contain traces of pig's blood, with a warning that religious groups could find its undisclosed presence very offensive.
The Dutch research has identified 185 different industrial uses of a pig, which includes the use of its haemoglobin in the cigarette filters.
The research offered an insight into the otherwise classified world of cigarette manufactures, and it was likely to invite concerns from devout Muslims and Jews, says Prof Chapman.
Religious texts of both of these faiths particularly ban the consumption of pork.
I think that there would be some particularly devout groups who would find the idea that there were pig products in cigarettes to be very offensive, said Prof Chapman.
The Jewish community certainly takes these matters extremely seriously and the Islamic communities certainly do as well, as would many vegetarians.
It just puts into hard relief the problem that the tobacco industry is not required to declare the ingredients of cigarettes ... they say 'that's our business' and a trade secret.
According to the Dutch research, the pig haemoglobin - a blood protein - found in cigarette filters was effective at trapping harmful chemicals before they enter the smoker's lungs.
While tobacco companies have voluntary shared the contents of their products on their web sites, they also noted undisclosed processing aids ... that are not significantly present in, and do not functionally affect, the finished product, comments Prof Chapman.
He says this catch-all term hidden from public view, an array of chemicals and other substances used in the making of tobacco products.
At least one cigarette brand sold in Greece was confirmed as using pig haemoglobin in its processes and the status of smokes sold was unknown, says Prof Chapman.
If you're a smoker and you're of Islamic or Jewish faith then you probably would want to know and there is no way of finding out.