Lawyers are considering legal action against British American Tobacco (BAT) on behalf of former employees given free cigarettes as part of their job.
Leigh Day is acting for former salesman Simon Neale, 57, who has inoperable lung cancer, and said it would examine other cases against the tobacco giant.
Mr Neale began working for Rothmans in 1982 and was an employee for four years, working in the South West region. Rothmans merged with BAT in 1999.
The father-of-three was given 1,200 cigarettes a month to give away or use, becoming a regular and heavy smoker. He often had 30,000 cigarettes in a safe in his car boot.
Mr Neale was diagnosed with inoperable lung cancer in late 2018, while he was still a smoker. He has since quit.
He said: "It's staggering looking back on it, but I was told when I joined the company that I'd be getting 1,200 free cigarettes a month.
"Working at Rothmans, I went from being an occasional smoker, a social smoker, to being a heavy smoker because I had so many cigarettes given to me.
"Last autumn, I was diagnosed with inoperable lung cancer and it knocked me for six. The worst thing was telling the children. The lung cancer has all come about from me working for Rothmans."
Deborah Arnott, chief executive of Action on Smoking and Health (Ash), said tobacco executives knew of the dangers of smoking.
At BAT's annual general meeting on Thursday, the charity will be calling on the company to reveal full details of its policy of handing out free cigarettes to employees and the public.
Ms Arnott said: "Simon Neale is not the only one. Many thousands of employees were given free cigarettes and free cigarettes were also doled out to the public.
"Big Tobacco promoted its products while hiding from the public - and its own employees - its own evidence that smoking was heavily addictive.
"We'd encourage anyone now suffering serious smoking-related disease who took up smoking before the 1990s to come forward and tell us their story.
"Big Tobacco must be called to account."
Simon Cleverly, group head of corporate affairs at BAT, said: "Historically, BAT employees had the option to receive a monthly allowance of cigarettes.
"At all times, these products complied with all applicable laws and regulations, including the relevant health warnings.
"In a small number of markets - six out of approximately 200 - this allowance continues as a result of collective bargaining agreements with local trade unions, and the products supplied comply with all applicable local regulations, including health warnings."
Leigh Day partner Richard Meeran, acting for Mr Neale, said: "We believe that giving employees huge quantities of highly addictive, powerfully cancer causing cigarettes, free of charge, and placing them in a work environment in which they are encouraged to smoke, is a flagrant breach of an employer's duty of care."