Commerce Secretary John Bryson is being investigated for two car crashes - including a hit-and-run accident - near his Los Angeles-area home over the weekend that department officials linked to a seizure that made him pass out behind the wheel.

Bryson, who oversees several federal agencies and focuses on business issues, was hospitalized in California but returned to Washington Monday while police continued their probe, said Commerce Department spokeswoman Jennifer Friedman, according to Reuters.

Bryson, who was in California to deliver the commencement address at his daughters' Pasadena prep school, returned to work as usual Monday at his office in Washington and made no public appearances or statements as of late afternoon, The New York Times reported. 

President Barack Obama is concerned about Bryson's health and broadly about the incident and believes he has functioned effectively in his post, said White House spokesman Jay Carney, who brushed aside questions on whether Bryson remained fit to serve.

The incident raises questions about Bryson's health and his future leadership at the agency as Obama is courting business leaders in his bid to win a second term in November.

Asked whether Obama was aware that Bryson had any kind of medical condition when he picked him, Carney would only say: The president nominated Secretary Bryson to serve because he felt he was capable of doing the job.

White House officials said that Bryson had told them that he did not recall the events leading to the accident.

Bryson passed a breathalyzer test at the scene, and submitted to a blood toxicology test, said Steve Whitmore, a spokesman for the Los Angeles County Sheriff's Office. If the report came back negative, he said, Bryson would not be charged.

There were no significant injuries, or heavy vehicular damage, in the accident, which took place shortly past 5 p.m. on Saturday.

Bryson, an energy expert and seasoned businessman, has held the job for less than a year.

Police in Southern California said Bryson was found unconscious on Saturday behind the wheel of his Lexus after crashing into the same car twice, leaving the scene and then colliding with another vehicle. At least one crash is being investigated as a felony hit-and-run.

It was not immediately clear whether the seizure led to either of the car crashes or if Bryson, 68, has been diagnosed with any underlying illnesses. A Commerce official said he had never had a seizure before.

We cannot confirm the exact timing of the seizure, the cause of the seizure or the sequence of events, the official said. The secretary was driving alone and at this point he has a limited recall of the events.