Saca held office from 2004 to 2009 for the rightist Nationalist Republican Alliance.
The court yesterday ordered that five bank accounts linked to Saca and his wife be frozen. It also ordered the temporary seizure of several properties linked to the ex-president.
It said Saca had not clarified the origins of USD 5 million of the USD 6.5 million in assets he acquired during his time in office.
Saca, a former radio sports announcer, declared his fortune at USD 3.6 million when he took office. Five years later, it had grown to USD 13.1 million.
Former President Mauricio Funes who succeeded Saca is also under investigation of illicit enrichment. And former President Francisco Flores was awaiting trial for his alleged diversion of millions of dollars in earthquake aid to his political party before he died in January of a cerebral hemorrhage.