"The preparations are in full swing, but the tests will be carried out early next year," V.K. Aatre, scientific adviser to India's defence minister, was quoted as saying by the Press Trust of India (PTI) news agency.

In April, Defence Minister George Fernandes said tests of the third variant of New Delhi's nuclear-capable Agni (Fire) missile were "overdue" and would be held by the end of this year.

A long-range missile was required for putting in place a credible nuclear deterrent, the minister said.

The Agni-III, powered by solid fuel, would be able to carry a one-tonne nuclear warhead and have a range of more than 2,000 kilometres (1,240 miles), Fernandes had said.

According to reports, India began developing the Agni-III missile in 1999 and it could achieve a range of 5,000 kilometres (3,100 miles).

Two other variants of the missile -- the Agni-I, with a range of 700 kilometres (437 miles) and the Agni-II, with a 2,000 kilometre (1,240 mile) range -- were at present being inducted into the military, Aatre said.

SPACE.WIRE