Video report by ITV News Correspondent Richard Pallot
A former British Army officer who lost almost £1 million through gambling believes the Government has "a lot more to do" to protect players.
Justyn Larcombe, who developed an addiction after being offered a free £5 bet, thinks gambling companies sometimes target people known to bet.
His comments come ahead of the Government's long-awaited review into the controversial industry.
The review - which will be published on Tuesday - is expected to pay particular attention to fixed-odds betting terminals (FOBTs), which have been described in the past as "as additive as crack cocaine".
An ex-gambling employee also told ITV News that betting firms target people, regardless of vulnerability, with offers of free bets to play.
Players' backgrounds aren't "even a question" for some companies, ITV News was told.
In the last year, £13.8 billion was spent in the UK by gamblers, of which an estimated £2 billion was spent on FOBTs.
Mr Larcombe left the Army to pursue a successful career in London, something which was shattered by his two-year addiction.
He told ITV News his addiction went on for longer because it was "so easy" to hide from his wife.
"I used to put my suit on in the morning, get in the car. I'd drive a couple of miles down the road and pretend I'd gone to work," he said.
"And I'd be sitting there on my smartphone just gambling."
Even after the climax of his addiction and moving back in with his parents, Mr Larcombe said he still had to content with gambling offers being advertised online.
"I self-excluded myself. So I clicked the button that said 'I don't want to gamble on this site' anymore," he said.
"But the trouble is there are two and a half thousands gambling sites.
"So two weeks later when I got an email to say 'here's a £50 free bet if you sign up with us' I convinced myself that that was OK.'"
Mr Larcombe believes the Government has a lot more to do to protect people from gambling.
A former online gambling site employee, whose job included luring in players, told ITV News he was tasked with targeting people indiscriminately.
"It's definitely immoral but there is nothing in legislation which prevents a gambling company to target people in that way," he said.
"We were told to send them as many players at the lowest cost and we got paid to do so."
The employee said it "wasn't even a question" what the players' backgrounds were for the firms - income or vulnerability.
"It was just a matter of people spending money on their sites," he told ITV News.
The UK is the only developed country in the world which allows up to £100 to be placed per spin in a shop on the high street.
Currently those who believe they have a gambling problem can apply to have themselves self-excluded from the 9,000 bookmakers across Britain.
A spokesperson for the Gambling Commission said: "We expect gambling operators to market their products responsibly in line with advertising rules to ensure they are socially responsible.
"Where operators fail to do this we will not hesitate to use our powers to hold them to account."