Experts have slammed a renovation project on a pyramid after it was clad in granite blocks.

The renovations on Egypt's Menkaure pyramid at Giza has been likened to "straightening the Tower of Pisa" by experts.

However, Egyptian officials have praised the renovations, with the Head of Egypt's Supreme Council of Antiquities Dr Mostafa Waziri calling them the "the project of the century."

In a video posted on Facebook, Waziri showed workers setting crude and chunky blocks of granite on the base of the pyramid, which sits besides the sphinx.

Work taking place on Egypt's Menkaure pyramid

As workers toil beside the juxtaposing grey and golden blocks, Waziri gestures as he informs viewers about the process.

However, the footage drew ire from commentators, who noted the "ugly" aesthetic of the pyramids.

Egyptologist Monica Hanna said: "Impossible! The only thing missing was to add tiling to the pyramid of Menkaure! When are we going to stop the absurdity in the management of Egyptian heritage?

"All international principles on renovations prohibit such interventions."

Dr Mostafa Waziry speaking to crews

She called on all archaeologists to "mobilise immediately".

When the pyramid was first built, it was encased in granite. However, over time it lost part of its covering.

The current renovation aims to restore the structure's original style by reconstructing the granite layer.

Waziri called it: "Egypt's gift to the world in the 21st century."

The issue of heritage preservation in Egypt, which derives 10 per cent of its gross domestic product from tourism, is often the subject of heated debate.

Egypt's Menkaure pyramid at Giza

The debate has lately focused on the 15th-century Abu al-Abbas al-Mursi mosque in the coastal city of Alexandria.

Local authorities announced an investigation after a contractor in charge of renovation on the mosque decided to repaint in white the ornate, carved and coloured ceilings.

Meanwhile, in Cairo, recent destruction of entire areas of the city's historic area led to powerful mobilisations by civil society.

This is largely banned from political activity and now concentrates the bulk of its fight with the government on urban planning and heritage issues.