"We have original, glazing print and a perfect product with security thread and watermarks that are almost undetectable in bare eyes," reads a part of an advertisement recently posted on Facebook to sell fake notes.

A Facebook user named "Jal Takar Dealer", in the same post also mentioned they deliver counterfeit notes across the country.

However, this user is not a lone "dealer".

Law enforcers said they have identified at least 50 Facebook users, pages or groups, where such advertisements are frequent, namely Jal Taka, Jal Taka Bikrir Dealer, Jal Taka Asol Dealer, A great- (Jal Taka), Jal Taka Bikri Kori, Jal Takar Babossa.

On June 4, a potential buyer of fake notes, Mohammod Rokibul Ahmed Rakib (according to his Facebook ID) commented on the said post and asked for a contact number, to which, the dealer replied with a number.

This correspondent called the number on Sunday night when the seller brazenly said he would supply fake notes anywhere in Dhaka or other districts without any hassle.

"You can pay cash on delivery. However, you don't need to pay in advance. Just the delivery charge would do -- Tk 180 inside Dhaka and Tk 300 for elsewhere," he said.

Other advertisers often take 50 percent of the payment in advance. They ask the potential buyers to contact them on Facebook Messenger or the WhatsApp number shared with their posts.

Some of these accounts have several thousand friends. The pages have over 2,000 followers, while there are over 3,000 members in a Facebook group used for selling fake notes.

The sellers share photos and videos of the fake notes in their posts. They also share screenshots, featuring satisfied customers, thanking them for delivering the package without any hassle.

When this correspondent went undercover to contact these dealers on messenger apps, one of them claimed that he used the notes himself and confirmed that it cannot be detected without machines.

The seller also shared a screenshot of his communication with other customers. He demanded 50 percent of the payment in advance before sending the fake notes via courier service.

The sellers advertise selling 1,00,000 fake notes of Tk 1,000 -- ranging from Tk 12,000 to Tk 20,000 -- based on the quality. The same amount of Tk 500 notes was being sold at a range from Tk 14,000 to Tk 20,000. Several were seen advertising fake notes of Tk 20, saying this note is easy to inject into the market as people usually do not bother to check it.

Law enforcers said that most of the online fake note sellers are frauds, as after getting the delivery charge or partial payment, they stop all communication with potential buyers on multiple occasions.

Police arrested at least five people involved with the online sale of fake notes.

"If the offline fake note sellers join hands with the online sellers, the situation may turn alarming," said a mid-ranked official of Dhaka Metropolitan Police, seeking anonymity.

Mashiur Rahman, deputy commissioner (DB) of Lalbagh Division, led several drives against fake currency producers. During these drives, many manufacturers were arrested and several counterfeit note factories were busted in the last couple of years.

Speaking with this correspondent, Mashiur said a section of people is involved in fake note trade offline. However, most online fake note sellers are frauds.

"Buyers of these notes are also criminals and they have no provision to lodge a complaint with police after they are cheated in the deal they struck with the fake note sellers," he said.

Mashiur, however, said law enforcers are on a high alert regarding such advertisements on social media.