The vaulted ceiling of France’s fire-ravaged Notre-Dame Cathedral could collapse as a result of the extreme heatwave currently gripping Paris and much of Europe, the building’s chief architect has warned.

The centuries-old national landmark was almost destroyed when a blaze broke out on April 15 this year, gutting the building and sending its central spire tumbling down in flames.

But with Paris experiencing scorching record temperatures of over 41° Celsius, the now water-logged stone and masonry is at risk of drying out too quickly, causing it to crumble, said chief architect Philippe Villeneuve.

"I am very worried about the heatwave. What I fear is that the joints or the masonry, as they dry, lose their coherence, their cohesion and their structural qualities and that all of sudden, the vault gives way,” he said.

Though sensors have been placed around the cathedral to monitor changes in its structural integrity, engineers have not yet been able to access the ceiling to directly assess the damage.

Work is still underway to remove charred debris from the cathedral and make the structure safe to begin restoration.

French President Emmanuel Macron has vowed Notre-Dame will be rebuilt within five years, though doing so is likely to cost billions of euros.