"The probe will start before the end of the spring; I can't give a more precise timeframe yet," said Oleg Mitvol, deputy head of the Federal Service for the Oversight of Natural Resources.
Asked why the probe had been moved back by almost six months, from January 1, he explained that there was a shortage of experts to study the situation on the ground.
The head of the environment agency said last month that Russian-British joint oil venture TNK-BP had failed to manage its licenses properly, and that the agency cannot prolong them despite the company's repeated requests.
"We cannot transfer terms mentioned in the licenses from 2001 to 2009. Everything should be done on time," Anatoly Ledovskikh said.
With 1.9 trillion cubic meters of proven reserves, the 62.4% TNK-BP-owned deposit is crucial for the Russian government, which is pursuing ambitious plans to build a natural gas pipeline network to meet Asian nations' energy needs, in particular China, and to diversify its export destinations.
Ledovskikh said TNK-BP is facing transport problems because it expected Russian energy giant Gazprom to allow the company to use its pipeline instead of building its own.
Gazprom, which was appointed in 2001 to coordinate all gas projects in East Siberia and Russia's Far East, said in early December it might join the Kovykta gas project.
The two companies have discussed a cooperation project to build a unified network for upstream and downstream operations, and gas transportation in East Siberia and the Far East.
