Police in Brazil are investigating former President Jair Bolsonaro over allegations he harassed a humpback whale.

Bolsonaro said Wednesday that he had admitted to the Federal Police that he had approached a whale while riding a watercraft off the north coast of Sao Paulo state last June. But he said he had denied bothering the animal.

“No one can understand why I am under investigation by the Federal Police regarding whale harassment,” Bolsonaro told CNN affiliate CNN Brasil.

Police opened the investigation into the encounter after video footage emerged on social media showed a watercraft – with its engine still running – come within about 15 metres (50 feet) of a humpback whale. Investigators suspect that Bolsonaro was riding the vehicle at the time.

But Bolsonaro said he had given the animal he approached more space.

“I know that the legislation exists, it has to be complied with, but it doesn’t fit into what happened to me. I admitted I was 20, 30 metres (65 to 100 feet) away from the whale. I did not bother it in any way. I made it very clear to the police,” he said.

Bolsonaro was speaking to CNN Brasil at a hospital in Sao Paulo, where he was to undergo tests related to the injuries he sustained when he was stabbed during a campaign event in 2018.

He claimed the investigation into the whale encounter was “political” and part of a “relentless persecution” against him.

The far-right politician has been facing mounting legal challenges, including a police investigation into an alleged attempted coup plot to keep him in power after he lost the 2022 presidential election.

Last year, Bolsonaro was barred from running for political office until 2030 by the country’s highest electoral court for abusing his power and misusing public media during the 2022 election campaign.

After Bolsonaro lost the election by a narrow margin to leftist President Luiz Inácio Lula da Silva, his supporters rioted and broke into government buildings in Brasilia on January 8, 2023. Bolsonaro has denied inciting the violent attacks in the capital.