Research carried out at Victoria University suggests roll-your-own cigarettes may be more addictive than manufactured brands.
Loose leaf tobacco was found to contain higher levels of tar, which contains a number of addictive elements.
PhD graduate Amy Lewis also found the habits of those smoking rollies may increase addiction levels as they are often don't use filters and tend to draw in smoke more intensively than smokers of factory-made cigarettes.
She also says nicotine replacement therapies are often ineffective.
