The research by Swedish e-commerce start-up A Good Company and data analytics firm HypeAuditor jointly assessed 1.84 million Instagram accounts across 82 countries.
It found the three regions with the most fakes on the Facebook-owned platform are the US (49 million), Brazil (27 million) and India (16 million).
"The Instagram fraud is estimated to cost marketers close to $750 million globally in wastage in a market now worth about $1.7 billion.
Marketing firm Mediakix estimated that influencer marketing on Instagram alone could reach $2 billion by the end of this year from $1 billion in 2017.
"Companies are pouring money into influencer marketing, thinking that they are connecting with real people and not Russian bots. In reality, they are pouring money down the drain and giving away free products to someone who acquired a mass-following overnight," Anders Ankarlid, CEO of A Good Company, told PRWeek.
The rise in popularity of social media platforms has opened up a relatively new advertising economy driven by "influencer marketing".
While Instagram has over a billion monthly active users globally, its parent company Facebook has over 2.38 billion monthly active users and over 16 million people log in to Twitter every day. WhatsApp is another powerful platform which has over 300 million users in India.
The kind of reach that social media platforms have can offer some idea about how big the influencer marketing business could be.
With a wide array of social media analytics tool available online, it is not difficult to spot the right influencers for their advertising programmes. However, in India, it is difficult to distinguish between a paid post and a personal opinion owing to lack of user awareness.
In May, personal data of millions of celebrities and influencers were allegedly exposed on Instagram and a massive database was traced to Mumbai-based social media marketing firm Chtrbox.
The database contained 49 million records of several high-profile influencers, including prominent food bloggers, celebrities and other social media influencers, TechCrunch reported.
"Each record contained public data, including bio, profile picture, number of followers they have, location and private contact information," the report claimed.
Chtrbox is a web development company which pays to social media influencers to promote content. It describes itself as a platform for brands to collaborate with influential social media characters in India.
Instagram later said in a statement that initial investigations proved no private emails or phone numbers of its users were accessed improperly.
( With inputs from IANS )