SEOUL, South Korea — A former president of South Korea, Lee Myung-bak, was questioned by prosecutors on Wednesday on charges of bribery, embezzlement and tax evasion, a year after another ex-leader was arrested on corruption charges.

Mr. Lee, who was president of South Korea from 2008 to 2013, faced a bank of television cameras as he entered the Seoul Central District prosecutors’ office, where he had been summoned for questioning as a criminal suspect.

Prosecutors have questioned or arrested several of Mr. Lee’s former aides, as well as relatives and businessmen, as part of the investigation. The questioning of Mr. Lee was part of their effort to collect enough evidence to indict him.

“I feel dejected as I stand here,” said Mr. Lee, 76, offering an apology for causing “concern” among South Koreans. “I hope that I will be the last former president to stand here.”