The ASA has said it was watching 122 UK-based influencers and rules on ad disclosure were being followed just 35% of the time.
Four social media influencers have been rebuked by regulators for repeatedly failing to disclose advertising on their accounts.
Chloe Ferry, Chloe Khan, Jodie Marsh and Lucy Mecklenburgh are the first to be named by the Advertising Standards Agency on a dedicated webpage.
The ASA contacted each of them with a request for assurances that clear and upfront ad labels would be used on advertising posts in future.
Lucy Mecklenburgh was formerly on The Only Way Is Essex. But all four either failed to give such assurances or gave them but then reneged.
ASA chief executive Guy Parker said: "We prefer to work with influencers and brands to help them stick to the rules, but the first influencers to be named on this list have been given every opportunity to treat people fairly about their ads.
"It's not difficult: be upfront and clear when posts and stories are ads.
"If this doesn't bring about the changes we expect, we won't hesitate to consider further sanctions."
The four will remain on the list for three months and be subject to extra spot checks by the ASA.
In the meantime, other influencers could join them on the list if they too are unable to follow the rules.
Chloe Khan broke advertising rules while her account was being watched by the ASA.
If the new webpage fails to act as a deterrent, the ASA can take out its own adverts naming the influencers or it can work with social media platforms to have the offending content removed.
The influencers could also be referred to statutory bodies for possible fines.
In March, the ASA said it was watching the Instagram accounts of 122 UK-based influencers and said ad disclosure rules were being followed just 35% of the time.
Marsh has previously posted unauthorised health claims about food supplements.
Last month, Geordie Shore's Ferry, 25, was one of three reality TV stars reprimanded by the ASA for promoting debt advice service Debt Slayers without revealing that she was being paid.
In May, the ASA banned posts on TV personality Marsh's Instagram account which included unauthorised health claims about food supplements which were not being clearly marked as ads.
Former Celebrity Big Brother star Khan and former Towie star Mecklenburgh were found to have broken advertising rules during monitoring.
Source: Sky News