The threat came a day after an experts' panel appointed by India's highest court approved the breaking up of the 11-storey Blue Lady - originally the liner France - at the Alang shipbreaking yard in Gujarat state.

"The green signal for it to beach off Gujarat is illegal as the technical committee had no mandate to grant such clearance especially after its term expired on July 31," Greenpeace campaigner Ramapati Kumar said.

"In this case, the Supreme Court has been bypassed and we will challenge in court the committee's approval," Kumar said.

He said the ship contained 1 200 tons of cancer-causing asbestos in addition to other toxic materials such as polychlorinated biphenyls.

The 315m ship was allowed to anchor in Indian waters 70km off Gujarat in June and the court-appointed panel had said it could not be broken up until its contents had been determined.

Greenpeace and another environmental group, the Corporate Accountability Desk, accused experts of carrying out a "cursory and hurried" inspection before giving clearance for it to be broken up at Alang, the world's largest shipyard.

"The inspection of such a large ship was done in four to five days which is simply not possible - this is just a whitewash," Corporate Accountability Desk spokesperson Madhumita Dutta said.

The SS France was renamed the SS Norway and later the Blue Lady after being sold by its French owners in 1979.

The vessel set out from Port Klang in Malaysia on May 6 under tow after being sold to Indian shipbreakers by its Malaysian owners Star Cruises.

In February the ship was turned away by Bangladesh on grounds that it was too toxic to be dismantled there.

Workers in Alang have been clamouring for it to be broken up at the shipyard, saying they need the work.

In February the French government ordered home the aircraft carrier Clemenceau as it was travelling to Alang after a vociferous campaign by Greenpeace which said the ship was laden with toxic waste. - Sapa-AFP