An unholy row is threatening one of the most sacred places in Christianity - the Church of the Holy Sepulchre in Jerusalem.
The centuries-old site, where many Christians believe Jesus was crucified, is visited by hundreds of thousands of pilgrims and tourists every year.
A recent survey says that part of the complex, a rooftop monastery, is in urgent need of repair, but work is being held up by a long-running dispute between two Christian sects who claim ownership of the site.
Within the main building, dark-robed monks with long beards chant and swing incense as they conduct ceremonies in the many small chapels and shrines.
There has been a church on this site for 1,700 years. Over the centuries it has been destroyed and rebuilt several times - but some parts are very old indeed.
Various Christian denominations - Greek Orthodox, Armenians, Catholics, among others - have always jealously defended and protected their own particular parts of the site.
Disputes are not uncommon, particularly over who has the authority to carry out repairs.
For example, a wooden ladder has remained on a ledge just above the main entrance since the 19th Century - because no-one can agree who has the right to take it down.
The latest row is potentially much more serious.
The Deir al-Sultan monastery was built on part of the main church roof more than 1,000 years ago.
The modest collection of small rooms has been occupied by monks from the Ethiopian Orthodox Church since 1808.
But a recent engineering report by an Israeli institute found that the monastery and part of the roof were "not in a good condition" and that parts of the structure "could collapse, endangering human life".Click here to see a diagram of the Church
Although the Ethiopian monks have lived there for more than 200 years, after losing many of their rights within the main church, the Copts were in overall control of the monastery.
That's certainly how the Coptic Church interprets the "Status Quo" - the controversial 1852 decree, issued by the then-Ottoman rulers of Jerusalem, to put an end to the arguments among the church's various claimants.
The Ethiopian Church has a different view, saying that they have had a presence on the roof-top for even longer and that the question of the monastery's "ownership" has never been properly defined.
From a vantage point overlooking the disputed monastery, I discussed the "situation" with Father Antonias el-Orshalamy, General Secretary to the Coptic Church in Jerusalem.
"The Ethiopians were always there as our guests, but then they wanted to take control," says Father Antonias - referring to the night in 1970 when Coptic monks were all attending midnight prayers in the main Sepulchre church.
With the help of Israeli police, the locks in the Deir al Sultan monastery were changed and the keys given to the Ethiopians.
Subsequent Israeli court rulings, ordering that control be handed back to the Copts, have effectively been ignored - drawing accusations that Israel has shown political bias in favouring the Ethiopians over the (Egyptian) Copts.
Whatever the political and religious arguments, the Ethiopians remain in control of the ancient monastery and refuse to budge.
They will not entertain any suggestion that the Copts should have any say over repairs to the monastery and rooftop courtyard.
In that vein, no one from the Ethiopian Church would speak to us.
Coptic and Ethiopian monks have come to blows in the past but they are not the only ones who have allowed tensions to boil over.
Fights between monks from different sects in the Sepulchre are not uncommon and passions run high, particularly on important holy days.
Father Jerome Murphy O'Connor is a professor at the Ecole Biblique in Jerusalem.
"The whole spectacle is unedifying and totally un-Christian in nature", says the affable Irish priest, who has witnessed all sorts of church disagreements during his 40 years in the city.
"I'm not hopeful - either for peace in the Middle East or for peace in the Holy Sepulchre," laughs Father O'Connor.
The impact of age and of so many pilgrims visiting the rooftop monastery and the Sepulchre Church is taking its toll.
While the main church is said to be structurally sound, many parts of the roof in particular are in need of extensive repair.
The Israeli government says it will pay for the work to be carried out if the Copts and Ethiopians can resolve their differences. But after decades of hostility neither side is rushing to compromise.
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