Patricia Moreira, managing director of international secretariat of Transparency International, said Thailand’s score was 36 out of 100 last year, down from 37 a year earlier.

She explained that corruption undermines democracy, leads to a vicious cycle and weakens democratic institutions, eventually corruption becomes so ingrained in society that it cannot be eliminated.

Since 1995, the index is published annually by Berlin-based Transparency International, which ranks countries “by their corruption levels, as set by expert assessments and opinion surveys”.