Indian air force officials demanded the defective parts be replaced for free, but the Russian manufacturers insisted on payment saying the warranty period had expired, the newspaper said, quoting unidentified sources at the air force.

The report said air force officials have threatened to stall a long-term contract for supply and manufacture of the Sukhoi in India unless the warranty is extended to cover the replacement of the parts.

India has 28 Sukhoi planes, which with modification can carry nuclear weapons.

The report said the problems developed with the first lot of Sukhois that have completed on average 700 hours of flying time each since their arrival 25 years ago.

Russia, a Cold War ally of India, remains the country's largest supplier of military hardware, accounting for more than 70 percent of army, air force and navy equipment.

While India has increasingly been branching out to Western military equipment, Russian hardware is generally priced lower.

WAR.WIRE