The CEO of state-owned Oman Oil Company, Ahmad al-Wahaibi, was sentenced to a total of 23 years in prison on Thursday and fined RO5m ($13m) for accepting bribes as part of a continuing crackdown on corruption in the country.

The judge at the Court of First Instance in Muscat also convicted a second defendant in the case, Adel al-Raisi, a former aide to the minister of the now-dissolved economy ministry, of organising a bribe made by a senior official at South Korea-based LGI to Al-Wahaibi, and sentenced him to 10 years imprisonment.

A third defendant, the vice-CEO of LGI, who was named in court as Myung Jao Yoo, was found guilty of paying a bribe to Al-Wahaibi after winning a petrochemical project in Sohar Port in Oman. Myung was jailed for 10 years and fined RO4m.

Oman has launched a series of bribery trials over the past few months as part of a crackdown on corruption in the wake of the political unrest in 2011.

The first convictions in the trials were handed down in mid-January against the managing director and a senior manager of Oman’s biggest construction group Galfar Engineering & Contracting and the head of the tender board for the country’s biggest oil company Petroleum Development Oman.

Galfar’s managing director, Indian national Mohammed Ali, was fined RO600,000 ($1.6m) and sentenced to three years in prison, followed by deportation.

The fact that the government’s investigations have led to the downfall of such wealthy and influential figures is evidence of Oman’s commitment to preventing corruption in the oil and gas industry.