Top executives from a bankrupt California solar energy company pleaded the Fifth Amendment more than a dozen times Friday in a congressional hearing that went nowhere but gave members the opportunity to pose dozens of questions about the loss of a half billion dollars in government loans.

Solyndra Inc. CEO Brian Harrison and the company's chief financial officer, Bill Stover, had notified the House Energy and Commerce Committee they were going to invoke their Fifth Amendment right to decline to testify to avoid self-incrimination.

That didn't mean lawmakers didn't have questions for the executives, leading to complaints from committee Democrats that House Republicans were badgering the witnesses.

The Supreme Court has ruled it's considered prosecutorial misconduct when the government calls witnesses with the flagrant intent of questioning them to invoke their Fifth Amendment, said Rep. Henry Waxman, D-Calif.

Oversight Subcommittee Chairman Cliff Stearns, who led the hearing, said that Democrats had agreed to the format ahead of time.

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I agreed to the format. That doesn't mean I agreed to badgering the witnesses, said ranking committee member Diana DeGette, D-Colo.

Rep. Phil Gingrey, R-Ga., told Fox News that the members asked questions that they would have liked to have answers. But he said the executives used their Fifth Amendment rights becaise they feared their testimony would incriminate themselves.

"And indeed I think they would," said

Silence from the two executives will not stop committee leaders from pursuing their investigation into the $528 million loan Solyndra received from the Energy Department in 2009.

In a letter to Energy Secretary Steven Chu, GOP lawmakers said they were expanding their inquiry into the Solyndra loan, which has become a rallying point for Republican critics of the Obama administration's push for so-called green jobs.

Lawmakers said they want the administration to turn over all communications between the Energy Department and White House related to Solyndra, as well as all communications between Energy and the Treasury, which lent Solyndra the money.

Committee leaders said the Obama administration may have violated the law when it restructured Solyndra's loan in February in such a way that private investors moved ahead of taxpayers for repayment in case of default. The economic stimulus law provides for taxpayers to be ahead of other creditors in the event of bankruptcy or default.

"We are also determined to know why DOE allowed the taxpayers to be subordinated to the private investors during that restructuring in violation of the clear letter of the law. What we do not know is whether the Solyndra executives here today have something to hide. Was all the information they submitted to DOE accurate and complete?" added Stearns.

Deputy Energy Secretary Daniel Poneman said Thursday that the restructuring was "entirely legal," noting that another aspect of the law requires Chu and other officials to protect the overall interests of taxpayers. He said the restructuring accomplished that because it gave the struggling company a better chance to succeed.

Solyndra filed for Chapter 11 bankruptcy protection earlier this month and laid off its 1,100 employees.

The Fremont, Calif.-based company was the first renewable-energy company to receive a loan guarantee under a stimulus-law program to encourage green energy and was frequently touted by the Obama administration as a model. President Obama visited the company's Silicon Valley headquarters last year, and Vice President Biden spoke by satellite at its groundbreaking ceremony.

Since then, the company's implosion and revelations that the administration hurried Office of Management and Budget officials to finish their review of the loan in time for the September 2009 groundbreaking has become an embarrassment for Obama as he tries to sell his new job-creation program.

The Associated Press contributed to this report.