The former South Korean president Lee Myung-bak has been sentenced to 15 years in prison, becoming the country’s fourth ex-leader convicted of corruption.

He was also fined 13bn won (£8.8m) after Seoul Central district court found him guilty of bribery and embezzlement.

Lee served as president from 2008-13 and his conviction follows the jailing in April of his successor, Park Geun-hye, dealing a serious blow to conservatives in South Korea. Park is serving a 33-year sentence for corruption and was forced from office amid large-scale protests.

The 76-year-old did not attend Friday’s hearing as a protest against it being televised live. He has consistently denied the charges and said the proceedings were politically motivated. Prosecutors had sought a 20-year jail term.

The court ruled that Lee had accepted bribes from some of South Korea’s largest companies, including Samsung, and the country’s intelligence service. He was found to have embezzled about 24bn won through slush funds at an auto parts company called DAS. Lee claimed the firm belonged to his brother but the court ruled that he was the de-facto owner. “Bringing everything into consideration, heavy punishment for the accused is inevitable,” the court said.

South Korean politicians are often scrutinised for their cozy relationship with the country’s family-owned conglomerates, or chaebol, which control vast swaths of the economy. It has led to frequent accusations of criminality across the political spectrum.

During the trial, Samsung was found to have paid Lee about 6bn won in exchange for a presidential pardon for its chair, Lee Kun-hee, who was jailed for tax evasion.

The court also said it was wrong for Lee to continue to deny the charges against him, and admonished him for attempting to shift the blame on to subordinates. The former South Korean leader was indicted in April on 16 charges that included bribery, embezzlement and abuse of power.

Lee previously described the case against him as “revenge” after the liberal president Moon Jae-in, currently in office, was elected. Moon was chief of staff under Roh Moo-hyun, who served as president from 2003 to 2008 and killed himself in 2009 after he was questioned by prosecutors about alleged corruption during Lee’s tenure. Moon has accused Lee of targeting Roh in an effort to discredit liberal politicians.

Chun Doo-hwan, the president from 1980-88, and Roh Tae-woo, the president from 1988-1993, were convicted of bribery and sedition in 1996 but were pardoned a year later.