US internet firm says 'body of water' was never labelled on mapping service, though Iranians still take to web to cry foul

It might have been mentioned by ancient cartographers and can be found on almost any atlas, but the Persian Gulf, a source of national pride for Iranians, has no place on Google Maps.

In a rare show of unity between the authorities and opposition, thousands of Iranians have taken to the internet to express their anger at the fact that it is not named, a move they suspect was politically motivated. They say Google removed the Persian Gulf's label from its mapping service. Users who search for it are directed to the right place on the map but the name is missing.

A Google spokesperson told the Guardian the reports were exaggerated and that it had not removed the term Persian Gulf, saying that "the body of water" had not been labelled from the beginning, like many other places.

The Persian Gulf is surrounded by Iran and its Arab neighbours, including Saudi Arabia, United Arab Emirates, Bahrain, Oman, Qatar and Kuwait. The term is not disputed internationally, with the UN and western countries referring to it by name. Arab states, however, often refer to it as the Arabian Gulf. Many media outlets avoid the controversy altogether by simply calling it as the Gulf.

Iran's Irna state news agency reported that Google had deleted the Persian Gulf's label from its maps service. Bahman Dori, a deputy in the country's ministry of culture and Islamic guidance, accused the organisation of spreading lies.

He told Irna: "By removing the Persian Gulf from internet, Google would not be able to hide the truth."

According to Dori, the move was "damaging" and "harmful".

"The enemies would not succeed in hiding facts and evidences about the Persian Gulf," he said. "Such actions from organisations such as Google would not bear fruit and their visitors will lose trust in the information they provide. By spreading lies, they lose their credibility."

His comments have been echoed by other officials. Iranian media and blogs have devoted significant coverage to the issue and the country's internet users has taken to social networking websites such as Twitter and Facebook to offer their sentiments.

Unlike the online mapping service, the virtual globe programme Google Earth labels the region as both the Persian Gulf and Arabian Gulf. Google has been previously criticised by the Iranian regime. In January, Iran's police chief, Esmail Ahmadi Moghaddam, called Google "a spying tool".

The Persian Gulf is symbolically important to Iran, providing a vital link to its glorious past as one of the world's most important ancient civilisations and the Persian empire.

In response to the controversies, Iran has named one of its major highways after the body of water, has put its image on a bank note and has designated a national Persian Gulf day.

In mid-April, the visit by the Iranian president, Mahmoud Ahmadinejad, to Abu-Musa, a small island in the Persian Gulf, triggered controversy among Arab states. Iran regards the island as part of its territory but the UAE claims it has been occupied by Iran. The UAE officials' criticisms were echoed by other Gulf states. Beside Abu-Musa, neighbouring islands Greater and Lesser Tunbs are also part of the territorial dispute between Iran and the UAE.