Mixed martial arts fighter Geronimo dos Santos was found dead after going for a swim in the Amazon.

The body of the 45-year-old heavyweight known as “Mondragon” was discovered floating near a beach more than a mile from where dos Santos dove into Rio Negro, a tributary of the Amazon River, according to Brazilian media. Fire department divers found the veteran Brazilian fighter Monday. He’d been missing since Friday. Recovery efforts were reportedly hampered by strong currents and challenging terrain.

Dos Santos’ last MMA fight was in April 2019, according to ESPN’s records. He won 39 of the 60 bouts he fought over a career spanning more than 13 years.

Fight site MMA Fighting credits him with competing in 72 matches.

His last fight was a Bare Knuckle Fighting Championship bout against former UFC heavyweight Aleksei Oleinik. Dos Santos won that showdown convincingly in a first-round knockout.

He was reportedly expected to fight in UFC 153, but was barred from that 2012 event in Brazil after testing positive for hepatitis B. Dos Santos’ manager claimed his fighter was treated for the viral infection and cured. Dos Santos was released from his UFC contract following that cancellation.