Pitbull.

(The Hill) — House Oversight and Government Reform Committee Chairman Darrell Issa (R-Calif.) is demanding Energy Department documents relating to over $4.7 billion in loan guarantees for solar projects approved Sept. 30, the deadline for financing under the stimulus law.

Issa’s quest for documents — spelled out in an Oct. 7 letter to Energy Secretary Steven Chu obtained by The Hill on Monday — signals a deepening of his loan guarantee probe that joins the separate House Energy and Commerce Committee investigation of the failed solar panel manufacturing company Solyndra.

Issa’s letter, noting “concerns” that the $535 million guarantee for Solyndra in 2009 was rushed, says the same questions apply to the four solar power generation projects approved at the end of September.

“$4.75 billion in loan guarantees given on the last day of the program raise similar concerns that the evaluation of loan guarantees may have been rushed to meet the deadline,” Issa writes.

The letter seeks documents about the financing for First Solar, Inc., SunPower Corp. and Prologis, Inc. by Oct. 21. The documents include Energy Department communications with the companies involved, internal department communications, and communications with the White House.