He complained that currently there's no clear standard but only general categories that determine what should be disclosed. "Some departments even refuse to disclose under the premise of confidentiality, or give vague responses," he noted. "We urgently need to set up a specific information disclosure system, and make clear rules on what punitive measures will be taken should officials violate the rules."

Corruption on wheels

Official statistics show that vehicles make up the largest portion of expenditures on the "three public-funded consumption categories."

For example, Guangdong spent 864 million yuan ($142.21 million) on the three categories last year, of which 500 million yuan ($81.64 million) went toward vehicle purchases and maintenance.

"Reform concerning government vehicles should be regarded as the core method to further reduce officials' expenditure that are covered by public funds," said Ye Qing, Deputy Director of the Hubei Provincial Bureau of Statistics.

In December 2012, the central authorities issued rules aiming to cut excessive spending of public funds, with decreasing the misuse of government vehicles as one of the priorities.

However, the CPC Central Commission for Discipline Inspection (CCDI) circulated a notice in mid-November last year, citing 4,851 cases involving either the misuse of government cars for private purposes or the purchase of excessively luxurious cars. These two violations of the frugality guidelines accounted for one third of all that were recorded.

Plenty of government officials treat official cars as if they were personal property and use them to send their children to school, attend weddings and even go shopping or traveling in them.

It is also common for government departments to require subordinate enterprises or institutions to "temporarily transfer" vehicles whose prices go beyond their budgets to higher-level departments.

Some officials have been caught shielding vehicle plates or driving under the influence while in government cars. Last August, four people were killed when Xu Jianping, a deputy head of the forestry bureau of Nanchang, capital of east China's Jiangxi Province, drove drunk in an official vehicle.