A 4ft black stone idol of Lord Vishnu was stolen from Katauna village in Nalanda.

The idol, which was stolen on Tuesday, belonged to the medieval period (8-12 century BC).

Nava Nalanda Mahavihara (NNM), a deemed university in Nalanda, functioning under ministry of culture had documented the idol under the project - mapping of Nalanda, Rajgir and other areas of Magadh division comprising five districts, Gaya, Jehanabad, Nawada, Aurangabad and Arwal. Bihar Virasat Vikas Samiti (BVVS) heritage volunteer Deepak Anand said the idol was kept in the open at the village. 'We will report the theft of the ancient sculpture to the International Art Loss Register (IALR), London, so that there is an international alert and the auction of the sculpture is blocked in the black market.'

IALR is a private organisation based in London that maintains database of reported stolen artefacts and in collaboration with international law enforcement agencies and auction bodies facilitates their tracking and recovery.

There are large number of ancient sculptures scattered in the villages of Magadh and the Patna region. Lack of photographic documentation is biggest obstacle in checking the menace of artefact thefts because of which several sculptures have been stolen. Theft of several artefacts have not been reported anywhere. In recent years, the NNM, in cooperation with the village community, is doing a photographic documentation of neglected sculptures in villages.

'Photographic documentation is a big help in tracking the sculptures in international market,' he said.

A 3.5ft tall rare statue of Buddha in sitting posture that was stolen in May from Maher village in Gaya was recovered in November 2014 only after the theft was reported to the IALR. The smugglers found it impossible to sell it in the grey market and after six months abandoned the statue at a nearby agriculture field.

'It is a recent trend that dealers, museums, collectors, insurance companies, who consider acquiring or investing in art and artefacts, are expected to inquire about the origins of the objects they buy to make sure they were not stolen,' Deepak said.