While the social network restricts adverts promoting the sale or use of "tobacco products and related paraphernalia," it uncovered 108 company-sponsored pages for cigars, e-cigarettes, hookah tobacco and smokeless tobacco, more than half of which featured 'shop now' buttons for purchasing.
The study, published in The BMJ Tobacco Control, highlights loopholes within Facebook's tobacco policies which could be closed, said lead author Robert Jackler, MD, professor and chair of otolaryngology-head and neck surgery and principal investigator of Stanford Research Into the Impact of Tobacco Advertising.
An example of the imagery banned in adverts on Facebook relating to tobacco (Facebook)
"Clearly, there are a lot of policies with the laudable intent of keeping tobacco promotion and sales out of Facebook," he said.
"These policies are voluntary, and they're a sign of Facebook's commitment to social responsibility. With some 2bn users and an enormous volume of daily postings, Facebook has a daunting task of policing its content."
Jackler and other researchers found that while Facebook banned private individuals from buying, selling or trading tobacco products last summer, the provision had been removed by February 2018.
Facebook's current advertising guidelines, which applies to paid advert and commercial content, prohibit the use of phrases such as: "Buy cigarettes and e-cigarettes here today," but 58 of the brand-sponsored pages carried purchase links, with 71 featuring sales promotion.
Images of e-cigarettes, hookah pipes and other smoking paraphernalia are also non-compliant with current guidelines, but 107 pages featured such pictures, the report claimed.
The majority of the pages did not implement safeguarding measures to prevent users aged under 18 from accessing the pages, with 56 per cent of the brand-sponsored pages and 90 per cent of online vendors failing to filter out younger customers.
"Our hope is that our study, by highlighting the degree to which tobacco marketers evade Facebook's intended restrictions, will encourage the company to make a renewed effort to implement its well-intentioned policies," Jacker added.
A BBC investigation in March last year found counterfeit tobacco and cigarettes were being advertised and sold through Facebook's Marketplace pages.
The company said that content found to breach its commerce polices was always removed.
This article originally appeared in our sister title, iNews