With its bright colours and bold lines, the new fresco on display at a Chinese temple is certainly eye-catching. Unfortunately, it bears no resemblance to the delicate historical images it replaced – prompting anger and the sacking of officials who authorised the botched restoration.

The case is reminiscent of the ham-fisted retouching of an image of Christ in a Spanish church, which earned comparisons to a hairy monkey. That restoration was so spectacularly bad that an estimated 40,000 visitors flocked to Borja, near Zaragoza, to see it.

Whether the crude, cartoon-like images at the Yunjie temple in Chaoyang, Liaoning province, have the same pull remains to be seen. What is clear is that they have little in common with the delicate wall paintings that preceded them, in a hall built during the Qing dynasty (1644-1911).

Li Haifeng, a senior official with the Chaoyang government, said the official in charge of temple affairs and the head of the city's cultural heritage monitoring team had both been sacked. The party chief of the management office for Phoenix Mountain scenic area, where the temple is based, was given a warning.

Li told the state-run Global Times newspaper that the temple's abbot had applied for restoration permission, because the buildings needed maintenance work. But the area management office failed to request approval from the provincial government, despite instructions from the city to do so, and the work was done by an unqualified local company.

While the original frescos were badly faded and damaged, the new versions have horrified observers.

Li Zhanyang, an archaeologist with Henan's Culture Relics Bureau, condemned the local government as "uneducated, unreasonable and ignorant of the law". It warned that similar incidents happened each year.

"They just use the name 'restoration' for a new project," he said.

He complained he had not heard of anyone being punished with legal action in such cases, adding: "We have the law, but we don't implement the law."

He Shuzhong, the founder of Beijing Cultural Heritage Protection Centre, said most restorations were "over-restored". Experts as well as officials lacked understanding of the value of cultural relics and the need to preserve the original – rather than recreating or altering it. They also wanted to finish projects quickly, while real restoration was a process of scientific research requiring time rather than high levels of investment, he said.

"China's modern circumstances … lead to the situation where either no one cares about the cultural relics, or there is over-investment, and over-restoration," he added.

But He also blamed the Chinese public's aesthetic standards.

"Most Chinese people do not enjoy the beauty of ancient, real ruins. Instead, they like dazzling, new, high, big things … The restoration of old architecture, in the hutongs [narrow alleys in cities with traditional courtyard houses], at Badaling [a stretch of the Great Wall] and the Forbidden City are like this."

Wujiaofeng, the internet user who first highlighted the changes on his blog, wrote: "The last trace of history inside [the temple] has been erased".

* Additional research by Cecily Huang