A Health Lottery advert has been banned after the watchdog found it encouraged irresponsible and potentially harmful gambling.

The ad appeared on the Demand 5 video-on-demand service promoting a direct debit offer whereby consumers could have their first two weeks' play "free" as a refund if they paid for their tickets monthly.

An Advertising Standards Authority (ASA) report said: "The voice-over stated: 'This August save big money with the Health Lottery and our fantastic online direct debit offer. Just sign up online to play monthly by direct debit and we'll refund your first two weeks' play'."

It went on: "That's right, we'll pay for up to 40 lines played each draw, giving you an incredible £160 money back on us. And you'll never miss another draw again."

A complainant challenged whether the ad condoned or encouraged gambling behaviour that was socially irresponsible or could lead to financial harm.

The Health Lottery said the ad was not intended to encourage excessive play but to reflect that players who purchased 40 entries per draw qualified for the refund.

They said the ad was subject to a strict internal compliance and legal review, and pointed out that it featured the gambleaware.co.uk logo, adding that the Gambling Commission was aware of the promotion and had not raised concerns "in line with the complaint".

The ASA noted that the ad, through the voice-over and visuals, established an "upbeat" tone and focused on the maximum return.

It said: "We considered that this emphasis on a £160 refund, which required a commitment of £320, was likely to encourage consumers who would not normally have spent £40 on twice weekly draws to spend more than they otherwise would have done, to their detriment in some cases.

"We therefore concluded that the ad was irresponsible and condoned and encouraged gambling behaviour that could lead to financial, social or emotional harm."

It ruled that the ad must not appear again in its current form, adding: "We told The Health Lottery to ensure that their ads in future did not encourage or condone gambling behaviour that could lead to harm."