South Korea's Ministry of Food and Drug Safety said on Thursday that so called "heat-not-burn" electronic cigarettes contain more tar than regular tobacco products.
According to the Drug Ministry, the average nicotine levels of "heat-not-burn" e-cigarettes were also found to be similar to regular cigarettes.
Five substances classified as 'first level carcinogens' by the International Agency for Cancer have also been discovered in the "heat-not-burn" tobacco products.
The ministry's report concluded that there's no evidence to suggest these products are less harmful than regular cigarettes.