PARIS — The Louvre Museum must spend on safety and security instead of flash, a new report from France’s top court of auditors said, casting doubts on French President Emmanuel Macron’s billion-euro plan to build a new entrance for the museum and give Leonardo da Vinci’s “Mona Lisa” its own room.

The report, released Thursday, had been widely expected after a spectacular heist last month in which €88 million of jewelry once belonging to French royal and imperial families was stolen from the world’s most-visited museum.

The theft exposed the Louvre’s deteriorating state — long flagged by staff representatives — and prompted French Culture Minister Rachida Dati to announce an emergency €80 million investment in new surveillance equipment.

Though arrests have been made, the stolen goods have not yet been retrieved.

Faced with a “budgetary impasse,” the Louvre must “prioritize” and focus on “investments that are crucial to its future, in particular the upgrading of technical infrastructure, especially safety and security,” the auditors said in Thursday’s report.

The 154-page report, based on observations made between 2018 and 2024, notes that the Louvre increased its revenue by nearly 50 percent over that six-year period, but directed most of its new resources toward public-facing projects such as art acquisitions and temporary exhibitions.

Meanwhile, the museum fell “considerably behind” on infrastructural investments needed to address the growing number of visitors.

Macron’s project for a New Louvre Renaissance, announced with much fanfare earlier this year, has a total estimated cost of €1.15 billion, with “many risks of cost overruns given its complexity,” according to the report. The project poses “significant financial risks” and is based on a funding plan that is “fragile, to say the least,” the auditors said.

Though Macron has said the cost would be covered entirely by the museum’s own funds and private donors, the report noted that the project still carries a burden for public finances because of France’s generous tax credits for patrons.

The Louvre issued a statement criticizing the report’s methodology, saying several of the highlighted shortcomings had already been addressed and arguing that the New Louvre Renaissance project is “necessary” to “bring durable solutions to the museum’s structural problems.”

The French president’s office and the Culture Ministry did not immediately respond to POLITICO’s request for comment.