In July 2025, Frontiers’ Research Integrity Auditing team announced it was retracting 122 articles across five of its journals after uncovering what it described as “a broad and sophisticated network of about 35 authors” potentially colluding across a very large number of journals to undermine peer review. The case is one of the largest single-publisher exposures of coordinated reviewer-author collusion to date, and it illustrates a distinct misconduct pattern from the “authorship-for-sale” paper mills CASRAI has covered elsewhere: this network centered on undisclosed conflicts of interest and citation manipulation inside the peer-review process itself, not the outright manufacture and sale of fabricated manuscripts.
What Frontiers found
The 122 retractions were distributed across five journals: 53 in Frontiers in Psychology, 33 in Frontiers in Environmental Science, 29 in Frontiers in Energy Research, six in Frontiers in Public Health, and one in Frontiers in Ecology and Evolution. Most of the affected papers were originally published in 2022. Frontiers said the pattern involved reviewers and editors who had prior undisclosed co-authorship relationships with the authors whose manuscripts they were evaluating, alongside evidence of citation manipulation designed to inflate the apparent standing of network members’ work.
Frontiers’ investigation did not stop at its own journals. The Research Integrity Auditing team told Retraction Watch and other outlets it had identified more than 4,000 articles connected to the same network across journals owned by seven other publishers, indicating the collusion extended well beyond a single publishing house.
How the network was discovered
The investigation began with a single reader-submitted concern about a possible undisclosed conflict of interest in the peer review of one article. Because Frontiers publishes reviewer names alongside accepted articles, the underlying pattern was visible to an outside reader in the first place — a transparency feature that made the initial detection possible in a way it would not have been under fully anonymous review. That single flag led Frontiers’ integrity team to audit co-authorship and reviewing histories across the implicated authors, surfacing the broader network. Public discussion on PubPeer also tracked specific overlaps, including at least one case where the same individual served simultaneously as a reviewer, a prior co-author of the submitting authors, and a handling editor for the same article collection — exactly the kind of undisclosed role-stacking conflict-of-interest policies exist to prevent.
A collusion ring, not a classic paper mill
It’s worth being precise about what this case does and doesn’t establish. Frontiers characterized the network’s core behavior as coordinated peer-review manipulation — undisclosed reviewer conflicts of interest and citation manipulation — rather than the wholesale fabrication or purchase of authorship slots on pre-written manuscripts. That distinguishes it from the classic paper-mill model, where a broker sells finished (often templated or plagiarized) manuscripts and authorship positions to buyers with no involvement in the underlying research, as in CASRAI’s coverage of the RV University stolen-study Telegram case and the BuyTheBy dataset on paper-mill authorship pricing. The Frontiers case instead sits closer to a citation and reviewer-collusion cartel — a pattern also visible in CASRAI’s coverage of a 2026 chemistry-journal citation-cartel investigation — though the underlying mechanics, publishers, and networks involved in each case are distinct and shouldn’t be conflated. See CASRAI’s paper mill and peer review fraud dictionary entries for how these categories are distinguished in practice.
What Frontiers says it will do next
Frontiers said its integrity team would share the investigation’s underlying methodology and findings with other publishers on request, including through the STM Integrity Hub — the cross-publisher screening infrastructure CASRAI covers in its STM Integrity Hub guide and the coalition context in United2Act. The publisher also indicated it plans to deploy AI-assisted verification of reviewer and editor conflict-of-interest disclosures against co-authorship and citation history at submission time, rather than relying solely on self-reported disclosure forms.
Why it matters for research administrators
For research integrity offices, library scholarly-communications teams, and CRediT/contributorship reviewers, this case is a reminder that authorship and peer-review integrity failures aren’t limited to obvious manuscript-mill red flags like templated language or implausible turnaround times. A collusion network built on undisclosed prior co-authorship between reviewers and authors can pass through standard checks precisely because the underlying manuscripts may be genuine research — the failure is in role separation and disclosure, not fabrication. Institutions vetting publication venues or auditing faculty publication records should treat retraction notices tied to this network (and any retraction statement citing peer-review integrity concerns) as a prompt to check co-authorship and reviewing-history overlaps, not just plagiarism or data-fabrication signals. CASRAI’s NISO CREC entry covers the standard now used to communicate retractions and expressions of concern in a machine-readable, trackable way, and the existing Frontiers Collaborative Peer Review entry provides background on the review model in which this network operated.
Frequently asked questions
Is this the same case as the RV University Telegram authorship-selling incident?
No. They are separate, unrelated incidents. RV University involved a stolen dataset and authorship slots sold openly on Telegram — a manuscript-brokering paper mill. The Frontiers case involves undisclosed reviewer-author conflicts of interest and citation manipulation inside otherwise-submitted research, uncovered through Frontiers’ own integrity auditing. CASRAI covers both because they represent different failure modes within the same broader problem of coordinated authorship and peer-review misconduct.
How many articles were retracted, and from which journals?
122 articles across five Frontiers journals: 53 from Frontiers in Psychology, 33 from Frontiers in Environmental Science, 29 from Frontiers in Energy Research, six from Frontiers in Public Health, and one from Frontiers in Ecology and Evolution. Most were originally published in 2022.
Were other publishers affected?
Frontiers said its integrity team identified more than 4,000 articles linked to the same network across journals owned by seven other publishers, though those publishers’ own retraction decisions are separate from Frontiers’ 122 and were not itemized in Frontiers’ public statement.
What triggered the investigation?
A single reader-submitted concern about a possible undisclosed conflict of interest in the peer review of one article. Frontiers’ policy of publishing reviewer names alongside accepted papers made the underlying pattern detectable to an outside reader, which is what prompted the broader audit.
