Second Complaint Against Belgian Virologist Marc Van Ranst Never Investigated
An exclusive investigation by Het Laatste Nieuws has revealed that not one but two complaints were filed in 2024 against Professor Marc Van Ranst, the prominent Belgian virologist at KU Leuven’s Rega Institute. While the first complaint—filed by fellow virologist Professor Piet Maes—led to a well-being investigation, a second complaint from a lab employee alleging power abuse, scientific fraud, and misuse of HIV research subsidies was never investigated.
Background: The Van Ranst-Maes Conflict
Professor Marc Van Ranst rose to national prominence during the COVID-19 pandemic as a regular television commentator and public health authority, becoming one of Belgium’s most recognizable scientific figures. He leads a research group at the Rega Institute for Medical Research at KU Leuven, where his lab receives approximately €680,000 per year in RIZIV (National Institute for Health and Disability Insurance) subsidies for HIV/AIDS research.
In early 2024, Professor Piet Maes filed a complaint with a KU Leuven vice-rector about transgressive behavior by Van Ranst and his lab manager Elke Wollants. An external prevention service (IDEWE) conducted a well-being investigation that identified Maes—not Van Ranst or Wollants—as the problem, citing “far-reaching toxic behavior.” KU Leuven suspended Maes in summer 2024, but he successfully challenged the suspension in court, with a judge questioning the quality of the IDEWE investigation. KU Leuven ultimately terminated Maes’s employment in early 2026.
The Second Complaint: A Whistleblower’s Account
According to HLN’s investigation, a lab employee at the Rega Institute had contacted the newspaper as early as 2023 with an anonymous letter containing complaints about Van Ranst. In April 2024, the same whistleblower sent her letter to an external professor at KU Leuven—one not affiliated with the Rega Institute—who forwarded it to the university’s Confidentiality Unit (Vertrouwensunit) on April 15, 2024.
The anonymous professor told HLN: “The whistleblower wrote that she had no confidence in reporting about Van Ranst within the Rega Institute. She feared for her career if she did that. That’s why she chose an anonymous report to an external professor. I considered it my duty to forward the letter to a reporting point.”
A Complaint That Vanished
Despite being formally submitted, the second complaint was never investigated. KU Leuven says the whistleblower requested strict confidentiality, preventing any action. However, the professor who forwarded the complaint disputes this, stating he contacted the Confidentiality Unit multiple times in 2024 and 2025 and was never told that confidentiality would block an investigation.
“I contacted the Confidentiality Unit several times in 2024 and 2025, both by phone and email,” the professor said. “At no point was it said that no investigation could be conducted because I wanted confidential treatment. I also never said that the report should not be investigated.”
Emails seen by HLN show that in summer 2024, the professor was told his complaint had been “taken to heart” and was included in the IDEWE investigation—which it was not. “In the well-being report that followed, there is no trace of an anonymous complaint about Van Ranst,” the professor said. “I was wrongly led to believe that an investigation had been conducted.”
Two Investigations Now Underway
The revelation has prompted action. The government commissioner of KU Leuven received the anonymous letter and immediately notified RIZIV about potential subsidy fraud. RIZIV spokesperson An-Sofie Soens confirmed: “The complaint is currently being analyzed internally.”
The allegations include that HIV research subsidy funds were used to pay staff who were not conducting HIV research—a practice that would constitute fraud. A separate external investigation into other allegations, including power abuse and scientific fraud, is being prepared by the government commissioner.
Van Ranst’s Response
Marc Van Ranst told HLN he has no knowledge of a second complaint but stated: “They may absolutely investigate this thoroughly. I will cooperate.”
KU Leuven declined to comment on the investigations, stating only that if RIZIV’s probe reveals issues, “the KU Leuven will take the appropriate decision at that time.”
Broader Implications
The case raises systemic questions about whistleblower protection in Belgian academia and the handling of complaints against high-profile figures. As P-Magazine noted in its analysis, the story taps into a larger narrative about the scrutiny facing pandemic-era scientific authorities who were elevated to public hero status.
The conflict at the Rega Institute also involves substantial financial stakes. The previous HLN investigation reported that Professor Maes has filed a claim of €13.7 million against KU Leuven, alleging the university violated a communication ban imposed by a court.
What’s Next
RIZIV’s internal analysis of the subsidy fraud allegations is ongoing. The government commissioner is preparing an external investigation into the remaining allegations. Whether these inquiries will vindicate or implicate Van Ranst—and what consequences they may have for KU Leuven’s governance—remains to be seen.
As the anonymous professor who forwarded the complaint concluded: the question hanging over the Rega Institute is not only whether the complaints are justified, but also how it is possible that a second report reportedly received no visible follow-up for years.