NEW DELHI (AFP).- India's top court on Tuesday sharply criticised the government for failing to protect the Taj Mahal, the centuries-old monument to love which has been changing colour because of pollution.

The brilliant marble of the Taj Mahal -- a UNESCO world heritage site -- has acquired a yellow tinge over the years.

The colour of the marble "was first becoming yellow. Now it seems to be green and black," a Supreme Court bench said after reviewing recent photos of the monument.

The Taj Mahal has been slowly yellowing because of smog in the region. Insects also leave green stains on its rear wall, which faces the heavily-polluted Yamuna River.

Various methods -- including using mudpacks to draw the stain from the marble -- have been employed since conservationists first raised alarm about the decay.

Authorities also announced plans earlier this year to limit the number of visitors to reduce wear and tear.

But that seems to have done little to stop the decay.

"It appears that you do not have expertise or you have (it) but do not want to utilise it, or you do not care about (the Taj Mahal)," the court said.

"You all appear helpless. Money should not be the consideration.... We need to save it."

Supreme Court justices M.B. Lokur and Deepak Gupta gave Prime Minister Narendra Modi's government and the government of Uttar Pradesh state a week to respond.

This is not the first time the Supreme Court has criticised Indian authorities on the issue. In February, it warned that the state government's "ad hoc" approach was jeopardising the monument.

The Taj Mahal was built in the 17th century by Mughal emperor Shah Jahan as a tomb for his beloved wife Mumtaz Mahal, who died giving birth in 1631.

It has attracted some of the most famous people in the world, and is often a stop for world leaders on state visits to India. Diana, the late British princess, was famously photographed alone on a marble seat there in 1992.


© Agence France-Presse