Brazil’s former President Jair Bolsonaro denied wrongdoing after federal police searched his Brasilia home Wednesday morning in a case about alleged alteration of COVID-19 vaccination records.

Police said in a statement that they are investigating allegations that false data was entered into public health systems and vaccination cards were changed. The statement did not name Bolsonaro, but his records are among those police suspect were altered in order to meet requirements to enter other countries, including the U.S., according to a person familiar with the investigation who requested anonymity because he is not authorized to speak publicly about the case.

Six people, including two close Bolsonaro aides, were arrested as part of the probe, the person said.