In a landmark ruling, the UK's Advertising Standards Authority (ASA) on Wednesday directed four vaping companies -- including the all-powerful British American Tobacco (BAT) -- not to promote e-cigarettes on Instagram posts.

The posts showed models and celebrities such as Lily Allen holding e-cigarettes, reports the BBC.

The four vaping companies banned from Instagram are: British American Tobacco (BAT), Ama Vape, Attitude Vapes and Global Vaping Group.

These companies are accused of promoting e-cigarettes and featuring models who appeared to be under 25, which is banned under the advertising code.

"While the ASA ruling is great news, urgent policy change is needed from Facebook, Instagram and Twitter to prevent BAT and other tobacco companies from using social media to advertise their harmful products to young people around the world," the Campaign for Tobacco-Free Kids said in a statement.

In its ruling, the Advertising Standards Authority said it is banning six posts from BAT, including one wishing Allen good luck with an image of her holding a Vype e-cigarette.

The concerned body said any future vape posts "should not be made from a public Instagram account" unless "they would only be distributed to those following their account and would not be seen by other users".

In a statement, BAT said its online communications "aimed to impart factual information regarding products but stopped short of direct or indirect promotion".

"It used these platforms to interact with users when they ask questions or request information and to communicate factual information about Vype that adults vapers and smokers wanted".

Ama Vape said it had removed its post and reviewed its other social-media content.

Late last year, the US Food and Drug Administration (FDA) had banned the sale of most flavoured e-cigarettes in convenience stores and petrol stations across the country.