Aug. 19, 2009 (United Press International) -- U.S. prosecutors who won a $780 million fine against Swiss bank UBS (NYSE:UBS) said they would ask that the whistle blower in the tax fraud case be sent to jail.

At a Friday hearing, prosecutors will ask Judge William Zloch to sentence Bradley Birkenfeld to 30 months in prison, court papers show.

Birkenfeld has been convicted of one count of conspiracy to defraud the government after pleading guilty in June 2008 to helping billionaire Igor Olenicoff hide $200 million from the IRS, The Miami Herald reported Wednesday.

But prosecutors say Birkenfeld, a UBS banker who courted business from wealthy U.S. clients and helped them hide assets from the Internal Revenue Service, was not fully forthright with his information.

Prosecutors said Birkenfeld initially failed to inform authorities of his dealings with Olenicoff, who was once listed on the Forbes list of America's wealthiest citizens.

Birkenfeld's attorneys are pushing for probation on the grounds that Birkenfeld was cooperating with authorities even before his arrest.