This is contained in a statement by Mr Wilson Uwujaren, the Spokesman of The Economic and Financial Crimes Commission (EFCC) in Abuja on Thursday.
Uwujaren said the convict was arraigned before Justice Abubakar Umar.
He said the Polish woman would be sentenced alongside her company, Icon Media and Marketing Agency Limited.
He said Umar had reserved the sentence after the convict was found guilty of a one-count charge of fraud brought against her by the EFCC.
Uwajaren said Gilmaska was found guilty of forging and issuing a dud cheque of nine million Nara to Tayo Olugbemi sometime in 2012.
The spokesman said the convict was arraigned on Nov. 7, 2012, and she pleaded not guilty to the charge.