Russia is considering introducing a one-time voluntary windfall tax on big businesses as they are performing well financially, an official said on Wednesday.

"A voluntary contribution from business... is being discussed, a one-time contribution," First Deputy Prime Minister Andrei Belousov was quoted by RIA news agency as saying.

Analysts have warned that the Russian government may have to raise taxes if prices of crude fail to meet expectations this year. (Reporting by Reuters Editing by Gareth Jones)