BEIJING - Two more local official bodies have become embroiled in online criticism after being suspected of using taxpayers' money to buy luxury products.

These costly purchases, coming after a string of expensive purchases by other local authorities were exposed, have generated widespread outcry as legal experts said online supervision is playing an increasingly significant role in constraining government behavior.

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A purchase plan by Heilongjiang provincial public security department, originally put on the Heilongjiang government procurement website by its international cooperation office, was discovered and posted by a netizen on Tianya.cn on Dec 25.

The purchase list includes a 41,000-yuan ($6,200) computer, two 15,200-yuan computers, a 30,000-yuan laser printer, and a 3,300-yuan multi-function printer, which generated widespread suspicion of their necessity.

In an online response on Tuesday, the department said the expensive computer and the laser printer are needed to ensure investigations and a smooth functioning department in cooperation with the International Criminal Police Organization.

The Shuimogou district court in Urumqi also came under public criticism when its recent bid for two luxury massage chairs was disclosed online.

The bid, valid from Dec 21 to 24 on Chinabidding.com, contained very specific descriptions for the chairs -- for instance a powerful and diversified massage function -- but did not specify the brand.

Web users were quick to associate these needs with a massage chair that costs more than 50,000 yuan.

Facing the question of why a judicial department needs two massage chairs, a publicity official of the district surnamed Cai said the chairs were meant for retired workers at the court, but the bid has now been canceled since it generated "misunderstanding".

"Online supervision provides effective oversight of government purchases," Wang Xixin, a law professor at Peking University, said on Tuesday.

It is understandable that netizens were skeptical of unnecessary luxury government purchases, because the government has a tendency to overestimate prices in a public bid, Wang said.

According to China's Government Procurement Law -- in effect since Jan 1, 2003 -- austerity and transparency are two of its central principals, and government purchases should be open to public scrutiny.

Earlier this year, the State Council issued a draft rule for the implementation of the Government Procurement Law and solicited public opinion.

A final proposed regulation is still under deliberation.

Cao Yin and Li Yao contributed to this story.