According to Transparency International, which publishes the annual Corruption Perception Index, Bahrain fell from being ranked 27 with a score of 6.1 on 2003 to 53 with a score of 5.1 in 2012
Bahrain became a party with United Nations Convention against Corruption in 2010 after signing it in 2005.
Scores are on a 0-10 scale, 10 being best (least corrupt / bribery least necessary).
Alcoa-Alba corruption case, a $6m bribe case.
Corruption in Bahrain Wikipedia