The Archaeological Survey of India (ASI) has joined an international network for the return of priceless artefacts taken away during British rule, including the Kohinoor diamond and the Sultanganj Buddha.
ASI Director General Gautam Sengupta said the list of India's treasures held abroad was "too long to handle" and there was a need for a "diplomatic and legal campaign" for their restitution from institutions, including the British Museum, the Royal Collection and the Birmingham Museum and Art Gallery.
Speaking to The Independent newspaper, Sengupta said that after decades of unsuccessful unilateral lobbying, India was looking to join a campaign with the support of UNESCO, and other countries with longstanding complaints about the foreign ownership of their artistic riches, including Egypt and Greece.
"As efforts so far to reclaim stolen treasures have proved futile, UNESCO support is required for launching an international campaign to achieve this end.
"Not only India, various other countries like Mexico, Peru, China, Bolivia, Cyprus and Guatemala have also voiced the same concern to get back their stolen and looted antiquities and to join the international campaign," Sengupta said.
While underlining the need to be "realistic" about the chances of large numbers of items being returned, Sengupta said that a list of "unique items" that should be returned to their home countries was being drawn up by each of the participating countries.
"Once this list is ready, these countries will jointly initiate a series of steps, including a diplomatic and legal campaign to get back the lost treasures," he added.