Jaipur, July 28: Despite intensive digging for one and a half months, a breakthrough in history’s biggest-ever treasure hunt at the Jaigarh fort here is nowhere in sight.

According to informed sources, a firm indication of the existence of a 250-year-old treasure valued at Rs. 100 crores is likely to be available after they have dug another 15 feet beneath a water tank. Already they have dug up to 29 feet.

Senior income tax officials from Delhi will arrive here on July 30 to review the progress of the digging.

The digging has been undertaken on the basis of a map given to the income tax authorities last year by a gypsy who claimed that his ancestors were very close to Maharaja Sawai Jai Singh who founded Jaipur in 1727 A.D. The hidden treasure belonged to Raja Mansingh Commander-in-Chief of Mughal Emperor Akbar.

The authorities are said to have entered into an agreement with the former Jaipur ruling house to which the historic fort belongs. The family will get a share of the treasure if it is found. According to the map the treasure is hidden in underground vaults beneath one of seven water storage tanks 118 yards from a gate called “Shiv Pol”. The tank’s roof is supported by nine pillars and arches. The water in the tank was drained out earlier this month to facilitate digging.