Peruvians awoke to find nearly the entire back of the statue, perched on a barren desert bluff overlooking the Pacific Ocean, charred black.
A spokesperson with Peru's firefighting corps told RPP Noticias that two dozen firefighters responded to the blaze and that an early working theory was the "Christ of the Pacific" was purposely set aflame.
However police later told state news agency Andina that electrical cables for the statue's lighting had short-circuited due to humidity, sparking the blaze.
"Police security for the Holy Father's visit is assured," Col. Manuel Rivera said.
The 69-foot (21-meter) statue was donated by Brazilian company Odebrecht in 2011, and for many Peruvians it has become a sour reminder of the company's illegal maneuverings to court and bribe high-ranking officials in exchange for lucrative public works contracts.
In January 2017, vandals covered the statue in messages like "Out of the country Odebrecht."
Two former Peruvian presidents are accused of accepting money from Odebrecht, and current President Pedro Pablo Kuczynski narrowly escaped impeachment in December over his ties to the company. Opposition lawmakers uncovered documents showing Kuczynski's private consulting firm received $782,000 from Odebrecht more than a decade ago when he was serving as a government minister.
Kuczynski has denied knowing anything about the payments, saying he recused himself from all consulting business while in the position.
The Christ statue's burning comes five days before Francis is scheduled to arrive in Peru.
The pope has hoped to highlight the need to protect the Amazon rainforest during his visit, but Peruvians will be paying close attention to whether he addresses corruption. It's an issue close to his heart, and he has called graft more insidious than sin and a plague that hurts the poorest the most.
The statue cost about $1 million, Odebrecht said in 2011.
Alan Garcia, whose second stint as Peru's president ran from 2006 to 2011 and who's under preliminary investigation into whether he took Odebrecht bribes, has said he contributed about $30,000 out of his own pocket for its construction.
"I want it to be a figure that blesses Peru," Garcia said at the time.
Francis will arrive first in Chile on Monday. Authorities there are on guard after several Roman Catholic churches in the capital, Santiago, were firebombed with pamphlets left at one scene threatening the pontiff: "The next bombs will be in your cassock."
The pamphlets also extolled the cause of the Mapuche indigenous people, who are pushing for a return of ancestral lands and other rights.
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