The secrets of Tutankhamun's decaying tomb

Given the peace and quiet Tutankhamun enjoyed for three millennia, it has been a rough 87 years for him since he was discovered by Howard Carter in 1922. He was immediately relieved of his treasures; his tomb became one of the world's best-known tourist attractions, and finally, in 2005, his mummified corpse was hoiked out of its final resting-place to be studied by scientists.

The "boy king's" fame did not just cost him his privacy. His underground tomb, in Egypt's Valley of the Kings, is now suffering from the wear and tear caused by tens of thousands of sweaty visitors who each year make a pilgrimage to the underground chamber where he once lay sheathed in the solid gold death-mask that has become his trademark.

Most day-trippers come to soak up the atmosphere at the spot where Carter famously made a "tiny breach in the top left-hand corner" of a hidden stone doorway, before chiselling his way inside and declaring: "I see wonderful things." But in common with most mass tourists, these visitors have begun to threaten the very monument they come to admire.

Strange brown spots, apparently mould, have appeared on the walls of Tutankhamun's burial chamber. Its elaborate murals, which tell the story of his journey into the after-life, are now covered in dust and have begun to peel in places. The king's wooden coffin is losing flakes of gilded paint and may also be in the early stages of decay.

Now, in an effort to stop the rot, Egypt's Supreme Council of Antiquities has called in the experts. For the next five years, a team of scientists and Egyptologists from the Getty Conservation Institute in California will intensively study, then attempt to preserve this great archaeological wonder of the world.

Getting Tutankhamun's tomb to surrender its secrets is a painfully complex process. The project will, for the first time, map every inch of his burial chamber, establishing every substance that went into the paints and mortars with which it was constructed and decorated, and shedding precious light on the construction techniques used by the ancient civilisation that built it. "King Tut's tomb has very specific problems," says the team's director, Jeanne Marie Teutonico. "One is flaking [of paint], in a lot of places. The other is the brown spots on the walls. They've been there since Carter excavated, but some people think they're growing. And no one knows what they really are. Could they be fungus? Bacteria? Are they still alive? Can they cause harm? We need to find out."

The Getty team, which last week showed The Independent around its Los Angeles laboratory, talk like bookish versions of Indiana Jones, and dress in white coats. Having established exactly what the burial site contains, they hope to create a plan to conserve, rather than restore or retouch it.

Tutankhamun, who died about 1324 BC, was a long way from being Ancient Egypt's most powerful or important ruler, but his tomb is famous because of the sheer quantity of treasure discovered in it. Larger and more elaborate nearby tombs, which may originally have held more loot, were more easily discovered and, by and large, fell victim to looting a couple of millennia ago.

Adding to public fascination with King Tut is both the enduring mystery about how he died so young and the infamous "curse", which is supposed to have killed several members of the 1922 team that discovered the tomb, including Lord Carnarvon, the 1922 expedition's sponsor, who died shortly afterwards from an infected insect bite.

But popularity comes at a price. About six million people a year visit the Valley of Kings, about an hour outside the desert city of Luxor. For many of them, the highlight of the trip involves joining the crowds who troop inside the tomb, sometimes standing four rows deep on the viewing platform overlooking his former resting place.

This, so far as researchers can tell, is contributing to the decay. "The amount of visitors affects humidity inside," says Shin Maekawa, one of the research team, who is mulling over pages of data from within the tomb. "It's a small space, maybe 100 metres square, and each person in it will emit roughly 100ml of water vapour in an hour and produce the same amount of heat as a 100-watt bulb.

"We've been monitoring humidity levels inside, and they can range from 20 to 70 per cent. In the past it got up to 90. At higher levels, we get seriously worried about fungi activity. There's also a problem with dust; you can't vacuum the tomb, because it would damage it, so it has never been properly cleaned. But dust comes in through visitors' skin, hair and lint, so we need to work out what to do about it all."

On the team's initial visit to Egypt last month, they used state-of-the-art X-ray machines and lighting systems to analyse the exact substances present in the paint on the walls of the tomb, so they can work out how best to clean and conserve its murals. It is a painstaking process, in warm, muggy conditions. Analysing a single small section of wall can take hours.

The second part of their remit involves turning Tutankhamun's tomb into a more visitor-friendly attraction. Many visitors to the Valley of Kings, having fought through the crowds, feel underwhelmed at the burial chamber, because almost all of its contents – including all of the golden treasures – are now in the Egyptian Museum in Cairo.

The crowded, poorly-lit underground room, which can be accessed by just one narrow staircase, contains just his mummy (broken when Carter removed its death mask) and a stone sarcophagus containing one of the four coffins he was buried in, Russian doll-style (the other three are in Cairo).

It makes few concessions to educating visitors and is frequently criticised in tourist guides. From 2011, when the initial stage of the Getty Conservation Institute project is completed, they will try to give the tomb an air of pizzazz more commonly seen at Western museums and monuments.

"We could certainly improve on the visitor's experience," adds Ms Teutonico. "It's not great. We'll look at the lighting, installing railings on the stairs, and work on helping the presentation of the whole area. It also needs some kind of ventilations scheme: it's hot, and the air exchange is not very good. "

But all the changes, and arguably the monument's entire future, are dependent on the American interlopers sidestepping the famous yet long-disproved curse that is alleged to have befallen other foreign visitors who have tried to get to the bottom of the mysteries of King Tutankhamun's tomb.

"Some of the technical imaging we recently did had to happen in the dark," she says. "We had to get special permission to stay after the tomb was closed. It's completely black, completely silent, and very hot.

"But there is an incredible presence, this incredible feeling of time passing. It's an evocative place. The guards stayed upstairs, and they thought we were out of our minds. But so far so good: we've lived to tell the tale."

The boy king His life, times – and afterlife

*Born: 1341 BC, died: 1324 BC.

* Family: King Tut's genealogy has been a subject of debate, but he is most commonly thought to be the son of Akhenaten and Queen Kiya. Incest was not a problem then – he is thought to have married his half-sister Queen Ankhesenepatan (or Ankhesenamun as she was later known) with whom he probably had two daughters who died at an early age.

* Career: under his reign, which began at the tender age of 12, he oversaw big changes. As well as some personal transformations – in his third year as king he changed his name from Tutankhaten to Tutankhamun – he reversed his father's revolution by lifting a ban on the old gods and temples and moving the capital back to Thebes from Akhenaten. He also tried – and failed – to restore diplomatic relations with neighbouring kingdoms.

* Death: Tutankhamun's temple was small compared to those of other Egyptian monarchs. His and his wife's bodies were mummified with two small coffins believed to be their children.

* Afterlife: quiet until he was discovered by Howard Carter in 1922. His temple was swiftly pillaged and in 2005 his mummified corpse removed from his tomb. Has since prospered as a tourist attraction – despite his reputed habit of cursing foreign visitors.