An ancient manuscript has lead to a breakdown in relations between Iran and the British Museum.
Iran has said it will cut ties with the Museum, due to the latter's failure to lend an ancient Babylonian artefact to Tehran.
The artefact in question is known as the Cyrus Cylinder - described by worldwide experts, including the United Nations, as the world's earliest bill of rights.
Dating from the 6th century BC, the ancient bill of rights is depicted on a clay tablet, recounting in cuneiform the conquest of Babylon by the Persian King, Cyrus the Great.
The tablet describes Cyrus's conquering of Babylon in 539 BC and the restoration of the Babylonian's captives to their homelands.
Tensions over the loan have long-festered between London and Tehran. The latest row also coincides with increasingly heavy pressure from the West over Iran's alleged nuclear program.
According to Iran officials, the Cyrus Cylinder was to be lent to Tehran on Sunday to be featured in an exhibition.
The British Museum apparently postponed the deal, citing technical reasons. It has been suggested that post-election unrest following Iran's disputed June election might also be a factor.
The Iranian Vice President Hamid Baqaei - also head of the country's cultural heritage and tourism organisation - described the British Museum's conduct as "not acceptable."
"The Cyrus Cylinder has been turned from a cultural issue into a political one by the British," said Baqaei, according to news sources.
"[Iran] will sever all its ties with the British Museum, which has become a political institution."
The British Museum has reportedly expressed "great surprise" at Baqaei's announcement, saying that it informed Tehran and Baqaei himself earlier this month that the loan would happen in July.
In a statement, the Museum said that any such decisions were made, "independently of political considerations."