The Indian Air Force (IAF) has reportedly asked the state-owned Hindustan Aeronautics (HAL) to halt work on its Intermediate Jet Trainers (IJT) programme.
The new development follows the recent crash of a HAL-built Hawk advanced jet trainer (AJT).
The Financial Express citied an anonymous source as saying: "While an inquiry has been ordered for the Hawk accident, the HAL is failing in its IJT R&D where the timelines have been revised at least thrice if not more.
"The company has already taken close to Rsc6.3bn crore ($98.3m) from the government (for the IJT venture). The IAF has now lost its patience and has conveyed the same to both the ministry of defence and the HAL."
The aircraft manufacturer started design work on the IJT in 1997.
The IAF reportedly has a potential requirement of 200 to 250 HJT-36 IJTs.
Earlier, HAL indicated that the air force will be able to induct the aircraft this year.
However, the source stated that there are several tests still remaining to complete and the firm is yet to resolve issues related to the specifications given by the IAF.
Meanwhile, a senior official in HAL responded: "The majority of the tests have been completed in the case of the IJT except the spin test and armament trials for operational clearance later this year.
"And this will be followed up by the spinning of the aircraft, which will happen anytime now."