Precious Jerusalem fresco defaced

It is believed the only portrait of the founder of modern Georgian

Georgia has officially complained to Israel after a priceless fresco was defaced in Jerusalem.

The fresco - in the 11th-century Georgian-built Monastery of the Holy Cross - represents the legendary Georgian poet Shota Rustaveli.

In a letter, Georgia asked Israel to take all the necessary steps to investigate the incident.

The damaged fresco is believed to be the only existing portrait of the legendary 12th century poet.

"It is difficult to say whether the damage was premeditated," said Georgian Foreign Minister Salome Zurabishvili.

"But what is certain is that someone tried to erase it and Israel's archaeological police must take the matter into their hands," Ms Zurabishvili told reporters in the capital Tbilisi.

The damage was discovered on Saturday

"We demand an explanation," the minister added.

The issue has arisen just weeks before Georgian President Mikhail Saakashvili is due to make his first visit to Israel.

Shota Rustaveli is considered by many experts as the founding father of the modern Georgian language.

His best-known work - the epic poem The Knight in the Panther's Skin - describes in surrealistic terms the struggle between the forces of light and darkness.

Some Georgian historians also say Rustaveli is buried in the monastery.