Seoul, Feb 1 (IANS): North Korea retreated four notches in an annual international corruption ranking to 174th among 180 countries last year, a report by an anti-corruption watchdog revealed on Tuesday.

The reclusive North scored 16 out of 100 in the Corruption Perceptions Index (CPI) report issued by Berlin-based Transparency International, down two points from the previous year, reports Yonhap News Agency.

The index evaluates countries based on how corrupt their public sector is perceived to be, using data collected "by a variety of reputable institutions, including the World Bank and the World Economic Forum".

North Korea does "not have the basic institutional infrastructure -- such as mechanisms for administration and rule of law -- to form an integrity system", the watchdog said.

South Korea climbed a notch to rank 32th with 62 points, while Denmark, Finland and New Zealand shared the top with 88 points.

South Sudan was at the bottom of the list with 11 points.