A prosecutor said an upgraded indictment is likely in the criminal case against two Rudy Giuliani associates with ties to Ukraine.

Assistant US attorney Douglas Zolkind made the prediction during a pre-trial hearing Monday in the case against Lev Parnas and Igor Fruman.

The men are charged with using foreign money to make illegal campaign contributions. Prosecutors say the donations were made while the men were lobbying US politicians to oust the US ambassador to Ukraine.

The arrest of the men has brought new scrutiny to Giuliani, a former New York City mayor who is Donald Trump’s personal lawyer.

Giuliani has tried to get Ukrainian officials to investigate the son of Trump’s potential Democratic challenger, Joe Biden. Giuliani has said he knew nothing about illegal campaign donations.