This study attempts to detect papers originating from the Russia-based paper mill ‘International Publisher’ LLC. A total of 1,063 offers to purchase co-authorship on a fraudulent papers published from 2019 to mid-2022 on the 123mi.ru website were analysed. This study identifies at least 451 papers that are potentially linked to the paper mill, including one preprint, a duplication paper and 16 republications of papers erroneously published in hijacked journals. Evidence of suspicious provenance from the paper mill is provided: matches in title, number of co-authorship slots, year of publication, country of the journal, country of a co-authors and similarities of abstracts. These problematic papers are co-authored by scholars from at least 39 countries and are submitted to both predatory and reputable journals. This study also demonstrates collaboration anomalies in questionable papers and examines indicators of the Russia-based paper mill. The value of co-authorship slots offered by ‘International Publisher’ LLC from 2019 to 2021 is estimated at $6.5 million. Since this study only analysed a single paper mill, it is likely that the number of papers with forged authorship is much higher.
