A special investigation commission will announce on May 20 the official results of a probe into the latest failure of Russia's ill-fated Bulava ballistic missile, the Navy commander said on Friday.

The latest launch of the missile, which Russia hopes will be a key element of its nuclear forces, from the Dmitry Donskoy nuclear submarine in the White Sea ended in failure in early December 2009. Only five of 12 Bulava launches have been officially reported as being successful.

"The conclusions of the commission will be announced on May 20," Adm. Vladimir Vysotsky said.

He added that the Russian military had significantly improved the supervision of the missile manufacturing process because some experts had blamed inefficient quality control for being one of the main causes of the test failures.

The Bulava (SS-NX-30) is a three-stage liquid and solid-propellant submarine-launched ballistic missile (SLBM). It carries up to 10 MIRV warheads and has a range of over 8,000 kilometers (5,000 miles).

The missile has been specifically designed for Russia's new Borey class nuclear submarines.

The future development of Bulava has been questioned by some lawmakers and defense industry officials who suggest that the Russian Navy should keep using the more reliable Sineva SLBM.

The Russian military has insisted that there is no alternative to the Bulava and pledged to continue testing the missile until it is ready to be deployed with the Navy. At least four new test launches of the missile have been planned for the end of June.

NOVOROSSIISK, May 7 (RIA Novosti)