It is known as the Jewel of India – but the Taj Mahal could do with a little polishing.
The white marble mausoleum is to be given a mud-pack to remove yellow pollution stains, archaeologists have said.
It will be the fourth time in its history that the 17th century monument, which is set on the banks of the river Yamuna and one of the finest examples of Mughal architecture, has been cleaned.
The last mud-pack was applied in 2008, but high levels of pollution in recent years have left the Taj Mahal looking slightly the worse for wear.
“Due to increasing pollution in the city, the white marble is yellowing and is losing its sheen,” B M Bhatnagar from the Archaeological Survey of India told the Press Trust of India.
“To restore the natural look of the monument the chemical wing of the ASI has started preparations for a mud-pack treatment,” he said.
The cleaning procedure is said to be modelled on a traditional beauty treatment used by Indian women who apply "Multani mitti" (Fuller's earth) to their faces to keep their skin glowing.
Mr Bhatnagar said that affected areas of the Taj Mahal are covered in a 2mm-thick layer of Fuller’s earth, which contains high levels of lime.
“When it dries the flakes are removed from the surface with soft nylon brushes and washed with distilled water to remove impurities sticking to the surface,” he said.
The first mud-pack treatment took place in 1994: subsequent cleaning procedures were carried out in 2001 and 2008.