Jair Bolsonaro told a judge he tampered with his ankle monitor because a drug-induced hallucination made him believe the device was secretly recording him.
His arrest followed a midnight alert indicating the device had been interfered with. Authorities feared he planned to flee to an embassy.
Bolsonaro has been under house arrest since a Supreme Court ruling found him guilty of attempting a coup. His 27-year sentence was expected to be enforced soon.
Bolsonaro explained that the medications he had been taking triggered paranoia. Thinking the monitor was bugged, he used a hand tool to pry it open.
Analysts doubted his explanation due to inconsistencies with earlier statements. International leaders reacted cautiously to the news.
