Online casinos face a crackdown on exploiting gamblers’ superstitions, after the advertising regulator launched an investigation into one firm’s claims about certain games being “hot or cold”.

The Guardian understands the Advertising Standards Authority (ASA) is likely to uphold a complaint lodged seven months ago against PlayOJO, which advertised a feature last year that offered gamblers a “unique chance to see the games on winning streaks”.

“Switch between HOT or COLD to reveal the MOST and LEAST profitable games of the hour, updated every 5 minutes,” the website told players.

The online casino, which is licensed by the Gambling Commission and owned by the Malta-based company Skill On Net Limited, suggested they could either play “hot” games to see if they continued paying out or try to “change the luck” on games that were not.

The page on PlayOJO’s website that included the promotional material was not available at time of publication but could be found via cached versions. The feature was also promoted via a TV ad in which a tarot card reader gave a customer advice while secretly using the PlayOJO mobile phone app to inform her predictions.

Although the ASA has yet to make a final decision, a draft version of its recommendation seen by the Guardian indicates it will uphold a complaint that promoting the feature was “misleading” and “irresponsible”.

The ruling, if confirmed, will affect whether firms can exploit the “gambler’s fallacy”, the false notion that previous outcomes have any effect on what will happen next. An example of this is the mistaken belief that a roulette ball is more likely to land on a number because it has not done so for a while.

The ASA’s draft ruling warned that PlayOJO’s marketing did contain elements that suggested players could exert control over game outcomes, including the exhortation to “choose your destiny”.

Bookmakers have previously come under fire for advertising “hot” and “cold” numbers on fixed-odds betting terminals, the controversial digital roulette machines whose stakes were slashed from £100 to £2 after an outcry about their links to addiction.

However, the ASA’s draft ruling against PlayOJO is thought to be the first time a regulator has specifically targeted the feature, with potential implications for the wider gambling industry.

PlayOJO said it had not been requested to remove the page on its website offering the “hot” or “cold” feature and had not done so. However, it said it was “in the process of tweaking certain marketing materials” and had “therefore removed these pages from our site, to address specific concerns”, and would replace them soon. It added that the ASA may yet agree that the marketing did not breach the advertising code.

An ASA spokesperson said it did not comment on individual cases.

A spokesperson for the Betting & Gaming Council, a lobby group of which Skill On Net is a member, said it could not comment on individual cases.