A congressional commission this month said the funds had gone missing during Ramirez's time in charge.
A congressional commission this month said the funds had gone missing during Ramirez's time in charge, from 2004 to 2014, citing 11 cases of alleged corruption including overpricing of drilling rigs and a scandal over money laundering through an Andorra bank.
Ramirez, who denies the charges, had requested an injunction from the Supreme Court to block the investigation.
Opposition leaders in Congress had said they could use the probe to hold him politically responsible or take legal action against him.
A summary of the decision posted on the court's website said the injunction request had been granted. Ramirez, contacted by Reuters, confirmed the decision.
The report also accused other top executives including the company's current president, Eulogio Del Pino, of corruption.
PDVSA has been at the center of a number of corruption scandals over the years, the most recent case involving a group of Houston-based businessmen who pleaded guilty in the United States to running a $1 billion kickback scheme to obtain contracts.
Last year, financial authorities in Andorra intervened in a small bank called BPA following an accusation by the United States that it was linked to billions of dollars in laundered funds including money illegally taken from PDVSA.
Switzerland has given around $51 million in formerly frozen assets to the United States in connection with a U.S. investigation into alleged corruption at PDVSA, the country's authorities said on Tuesday.
Venezuela's opposition in December won a majority of seats in parliament and immediately began efforts to document corruption under the ruling Socialist Party.
The Supreme Court since then has repeatedly sided with the executive branch in its disputes with the legislature.