Paper mills often produce papers with fabricated data or sell authorships to researchers.Credit: Lane Erickson/Alamy
An investigation has identified more than 1,500 research articles produced by a network of Ukrainian companies that could be one of Europe’s largest paper mills — businesses that produce fake or low-quality research papers and sell authorships.
Anna Abalkina, a research-integrity sleuth and social scientist at the Free University of Berlin, discovered the paper mill in 20221 after spotting papers with author e-mail addresses that had domains that did not match the geographical locations of academic affiliations. She dubbed the paper mill ‘Tanu.pro’ after the most frequently used of these unusual domains.
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Abalkina later teamed up with Svetlana Kleiner, a research integrity officer at the publisher Springer Nature, who is based in Leiden, the Netherlands (Nature’s news team is editorially independent of its publisher.) Together, they traced more than 60 suspicious e-mail domains that were linked to Tanu.pro and appeared among the author e-mails of 1,517 papers published between 2017 and 2025, listing more than 4,500 researchers affiliated with around 460 universities across 46 countries. The majority of authors were in Ukraine, Kazakhstan and Russia.
“I was astounded by the sheer number and the sheer scale of this paper mill,” says Kleiner. She and Abalkina presented their findings on 3 September at the 10th International Congress on Peer Review and Scientific Publications in Chicago, Illinois.
Peculiar e-mails
During her investigation into a number of peculiar e-mail domains that cropped up on hundreds of papers, Abalkina established that one of the domains was registered to a founder of a Kyiv-based company called Scientific Publications, which was established in 2016.
On its website, Scientific Publications says that it offers services such as manuscript editing, translation and submission to journals that are indexed in Scopus and the Web of Science. It claims to be able to ‘boost citations’, and says that its customers are ‘legally protected’. At first glance, “they do look like a legitimate business that just facilitates submission,” says Kleiner.
But some of the wording on the website — such as “Order the publication of scientific article in high-rated journal right now” — implies that papers are produced to order or that authors can buy their way onto papers.
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The investigation also found that some of the papers by authors with e-mail addresses linked to Scientific Publications, along with other companies it is linked to through ownership, contain hallmarks of paper-mill publications: fabricated data, plagiarism, irrelevant citations and signs of efforts to manipulate peer review. The presence of e-mail addresses that do not match up with authors’ listed affiliations suggests that the paper mill is creating e-mail aliases for its clients that allow it to directly correspond with journal editors, Abalkina says.
Scientific Publications told Nature that it does not own or use the domain tanu.pro or others identified by the investigation. When asked whether or not the company produces papers to order, sells authorships or creates email addresses for its clients, a spokesperson for Scientific Publications said: “Technologies and working methods of our company are considered commercial secrets, as they provide us with a competitive advantage.”
“Over nearly ten years of work in scientific consulting, our clients have included tens of thousands of researchers from more than 60 countries, who have received high-quality, transparent, and reliable services,” they added. “Another important area of our activity is the prevention of ethical violations and the detection of academic misconduct. Our experts maintain ongoing professional contact with journalists, researchers and government agencies in different countries, advising them on issues of transparency and integrity in scientific publishing.”
Prolific paper mill
The Tanu.pro paper mill is “very prolific” and “what gets published is a very small part” of everything it produces, says Kleiner. Over the past few years, Springer Nature received 8,432 submissions linked to Tanu.pro, most of which were rejected, but 79 were published. Forty-eight of these have since been retracted.
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As part of the investigation, Kleiner compared 77 Tanu.pro papers published in Springer Nature journals with 77 articles that were from the same journals and publication years, and had the same number of co-authors but that bore no hallmarks of paper-mill production. She found that 44% of authors on the Tanu.pro papers had a senior university role such as professor or department head, compared with 30% in the control papers.
