The UNESCO team will make a visit in the last week of April to the 1,500-year-old temple at Bodh Gaya, about 110 km from Patna, an official told the agency over telephone.

The team will assess the physical condition of the temple, known as Buddhism's birthplace, to see if its maintenance guidelines have been violated.

The temple stands at the site near where the Buddha is said to have attained enlightenment some 2,500 years ago.

UNESCO officials are reportedly unhappy after a three-member expert committee last week complained after a visit that illegal concrete structures were mushrooming in and around the temple.

The UNESCO had been warning over the last two years that it would revoke the heritage status for the temple, if its maintenance guidelines continued to be flouted.

The temple was declared a world Heritage Site in June 2002, becoming the 23rd historical structure in India to be given the special status.

The Central and Bihar governments had assured Unesco that its guidelines - including the enforcement of a strict ban on all construction in a one-kilometre radius around the temple - would be strictly followed.

But new structures have come up within the restricted area. The matter has been reported regularly by local dailies.

The Unesco had, last year, asked Government agencies to stop the violation of its guidelines and threatened to de-list the temple from the heritage list.

Violations were also reported of another Unesco guideline that limits the height of structures near the temple to 11 metres.

The Bihar government had drawn up grand plans to develop the site into a major tourist destination after it was included in the heritage list.

A building boom followed, though the Government had agreed not to allow any construction in the buffer area.