Photographs of a Chinese city mayor apparently wearing expensive luxury watches have provoked widespread derision online, with some web users comparing officials to watch models.

Yuan Zhanting, the mayor of Lanzhou, the capital of China's relatively poor northwestern province of Gansu, is the latest Chinese official to be accused in social media of wearing expensive timepieces.

An Internet user posted pictures of him wearing a total of five luxury wristwatches, the state-run Global Times said. One of them, an Omega, was worth 150,000 yuan ($24,000).

Zhou Lubao posted the images on Sina Weibo -- a website similar to Twitter -- in protest at the Lanzhou government sentencing a woman to a year of re-education through labour, a local report said.

It quoted him as saying he had received multiple phone calls from authorities in Lanzhou and Beijing requesting that he delete the photos.

"Our officials are turning into models for luxury watches," one weibo user wrote.

Another said: "According to logic, officials who love expensive watches must love women even more... how many houses and how much money does he have?"

Yuan, 51, told a local newspaper that he had seen the pictures, adding that "the Gansu government is dealing with it" and declining to make further comments.

A statement posted on the website of Gansu's provincial government dated Wednesday said it was "paying great attention" to the images and was "already confirming the situation".

Yuan is not the first timepiece aficionado to have been ensnared by China's online commentators.

Yang Dacai, an official in the central province of Shaanxi, was sacked earlier this year after web users posted photographs of him wearing watches said to be worth more than 300,000 yuan.

A discipline commission also found he had committed "inappropriate 'smiling face' behaviour" by grinning at the scene of a fatal road accident.

But while China's 538 million Internet users are able to use microblogs to accuse local officials of corruption, posts making negative references to the country's most powerful politicians are regularly deleted by online censors.

Chinese mayors have substantial influence over government projects, but have a lower political status than Communist party secretaries assigned to each city.