The Advertising Standards Authority is investigating the trend of social media posts which superimpose the logo of the gambling company Stake on to viral images, many of which feature disturbing content.

Stake, the Australian bookmaker which has been Everton’s front-of-shirt sponsor since the 2022-23 season, has been accused of working with accounts on X to promote its brand via unofficial advertising campaigns which appear to contravene gambling rules. Although the majority of posts originate outside the UK they can be freely viewed in the country. The ASA is responsible for ensuring gambling adverts are socially responsible, with “particular regard” to the need to protect children.

After complaints about the posts the ASA has committed to looking into them and a spokesperson told the Guardian it was assessing the posts to see “whether there are grounds for further action”. The organisation said it was considering issues of “jurisdiction” around the posts and whether complaints should be referred to the Gambling Commission, which is tasked with enforcing any breaches of the advertising code around gambling.

Stake holds a “white label” licence from the Gambling Commission which allows it to operate in the UK. The licence obliges companies to comply with the UK advertising code. In relation to gambling, one of the code’s key aims is to ensure adverts are not “of strong appeal to children or young persons, especially by reflecting or being associated with youth culture”.

Most of the Stake-branded posts relate to content that could appeal to young people. The trend apes posts by the rapper Drake, who is sponsored by Stake and commonly wagers substantial sums on sporting events before posting images of betting slips with the Stake logo in a prominent position. A variety of viral accounts have been attaching the Stake logo. It has appeared on images of sports events and statistics, the promotion of Only Fans content and fight videos, and on apparently random images, such as bowls of hard boiled eggs.

The extent of the trend, and Stake’s involvement in it, remains unclear. Some accounts have claimed to have earned thousands of dollars from the practice and last month the owner of X, Elon Musk, promised the “annihilation” of accounts deemed to be engaging in “platform manipulation by buying large follower accounts and then using them to push paid narratives”. Although some of the most prominent Stake-posting accounts were suspended and remain inactive on the network, the trend goes on with influencers with hundreds of thousands of followers still posting the Stake logo.

Stake did not respond to a request for comment from the Guardian for this article and appears not to have commented publicly on a policy that has provoked intense debate online. There is a lack of clarity as to how the ads are placed, though some posts by influencers suggest individuals are approached through direct messages and offered individual payments for each post that features the logo.

Stake was founded in 2017 by Bijan Tehrani and Ed Craven, who also founded the right-wing streaming platform Kick. The bookmaker previously courted controversy by allowing users to bet in cryptocurrency. Stake has been approached by the Guardian for comment.