MPs are being urged not to let tobacco companies self-regulate if they consider further reforms to tobacco laws.

Former US tobacco company scientist, turned whistle blower and anti-tobacco campaigner, Dr Jeffrey Wigand, has told a Select Committee inquiry into the health impact of tobacco, that allowing the tobacco industry to self-regulate is like allowing the fox to build the chicken coop.

"If one reads their documents over the last 50 years, you will find out that self-regulation does not work. They will not voluntarily do anything, anything, whether it's morally right, whether it saves lives, at the expense of profit."

Dr Wigand said in the four years he worked in the industry he saw daily and deliberate distortions of the truth which he had to be part of.

"There are two scenarios. Scenario one is what I could say inside the company, that nicotine is addictive and that tar will kill you. Outside the company, I was not allowed to say that."

Dr Wigand says tobacco companies deliberately sanitise internal reports about tobacco and it effects to protect themselves against law suits.