A judge has ordered that a former treasurer of Spain's ruling party be held in jail while he awaits trial on charges of tax fraud and money laundering.

National Court Judge Pablo Ruz accepted Thursday the argument of prosecutors that former Popular Party finance chief Luis Barcenas represented a flight risk and denied him bail.

Barcenas was treasurer of Prime Minister Mariano Rajoy's Popular Party from 2008 to 2009 and a senator from 2004 to 2010.

He is accused of keeping up to 47 million euros ($61 million) in secret Swiss bank accounts. He recently told the judge he had earned the money through investments not related to his post as treasurer.

The case stems from an investigation into alleged illegal financing of the party, something the Popular Party denies.