Chennai, May 7: Government scientists have suggested that an islet chain in the Palk Strait is man-made, triggering claims that it is the remnant of the bridge Ram’s mythological monkey army built to Lanka.

The issue has raised political passions because a Rs 2,427-crore navigation project that will save the country Rs 1,000 crore a year requires the demolition of the ridge.

Adam’s Bridge, a series of sand-dune islets and shallows south-east of Dhanushkodi near Rameshwaram, links India with Talaimannar off the Sri Lankan coast. It has long been held locally to be the bridge Ram built to invade Lanka and rescue Sita, and is called “Ramar Setu”.

The Centre’s department of earth sciences has given an “opinion” to the government that the islets are probably a result of human activity.

The department, under the ministry of science and technology, says the sand dunes have a base of coral and sandstone that seem to have been “transported” from elsewhere.

Its unpublished report, of which The Telegraph has a copy, says the naturally formed corals in Lakshadweep, the Andamans or the nearby Gulf of Mannar grow vertically from a hard-rock base. But the Adam’s Bridge coral doesn’t grow vertically and appears to “rest” loosely on the seabed.

“The coral formations hardly occur 1 m to 2.5 m in length and rest on loose marine sands. Most… seem to be rounded pebbles of corals. These things appear to point that these… have been transported and placed in these areas,” the department’s note says.

“Since the calcareous sand stones and corals are less dense (and therefore lighter) than the normal hard rock and quite compact, probably these were used by (the) ancients to form a connecting link to Sri Lanka on the higher elevations of the Adam’s Bridge ridge and this is analogous to (a) modern-day causeway.”

The leaked report led to a ruckus in the Tamil Nadu Assembly on Friday. The Opposition, including the BJP, demanded that the ridge be spared and chief minister M. Karunanidhi hit back with accusations of a “north Indian” and “fundamentalist” plot to derail the project.

The Sethusamudram Ship Canal Project involves dredging the islets to deepen the Palk Strait and thus open a direct channel between India’s west and east coasts. Currently, ships have to make a detour around Sri Lanka.

The 167-km channel, dubbed the “Suez of the East”, will shorten shipping routes by up to 424 nautical miles (780 km) and sailing time by 30 hours, saving fuel. India’s import-export trade will save the Rs 1,000 crore a year it now spends in foreign exchange because of transhipment of cargo outside the country, through Colombo.

The Opposition ADMK, BJP and the Janata Party cited the “scientific opinion” to buttress their case that the project, for which dredging is under way, should find an alternative route.

“Suddenly, some communal elements have banded together to give this controversy a religious hue, attempting to create a bloodbath here, just as they did by demolishing the Babri Masjid in Ayodhya to build a temple to Ram,” Karunanidhi told the House. “Most of these people opposing the project are north Indian religious fundamentalists.”

ADMK chief Jayalalithaa has threatened to move court to stay the project if Adam’s Bridge is touched. The ridge, which she wants spared in deference to “people’s religious sentiments”, acted as a barrier during the 2004 tsunami, protecting large parts of southern Tamil Nadu and Kerala.