The South Korean president's brother has been arrested and taken to a detention centre after a court approved a warrant on bribery allegations, a major embarrassment to the ruling party in a presidential election year.

The Seoul central district court issued the arrest warrant for Lee Sang-deuk, the elder brother of President Lee Myung-bak, late on Tuesday. Hours earlier, as the suspect entered the court for questioning, enraged protesters threw eggs at him, grabbed his tie and jostled him.

Lee was taken from the prosecutors' office to the Seoul detention centre, according to an official who declined to provide further details such as his name, citing office rules.

Prosecutors accuse the former lawmaker of taking $500,000 (£320,000) in bribes from two detained bankers with the intent of using his influence to help the pair avoid punishment.

Lee did not speak to reporters gathered at the court, shaking off the protesters and media mobbing him before walking through a security checkpoint.

The protesters, many of them middle-aged women, said they had lost money after the government suspended the troubled savings banks from which Lee is accused of taking bribes.

Lee Myung-bak ends his single five-year presidential term early next year. Elections for the next president are due to be held in December.