Dr. Chu received the grant from BP’s chief scientist at the time, Steven E. Koonin, a fellow theoretical physicist whom Dr. Chu jocularly described as “my twin brother.” Dr. Koonin had selected the Lawrence Berkeley National Laboratory at the University of California, Berkeley, over other universities in the United States and Britain in part because of Dr. Chu’s pioneering work in alternative fuels.

Today, Dr. Chu is President Obama’s energy secretary, and he spent Tuesday in Houston working with BP officials to try to find a way to stop the unabated flow of oil from a ruptured well a mile beneath the Gulf of Mexico.

Dr. Koonin, who followed Dr. Chu to the Energy Department and now serves as under secretary of energy for science, is recused from all matters relating to the disaster because of his past ties to BP, said Stephanie Mueller, an Energy Department spokeswoman.

Dr. Chu, she said, “has never had a financial interest in BP.”