BEIJING, Dec. 21 -- Prosecutors in east China's Shandong Province have lodged a lawsuit against a county-level environmental protection department in the first ever prosecutors vs. administration public interest case, according to the Supreme People's Procuratorate (SPP).

The Qingyun Environmental Department is accused of "illegal acts" during its supervision of a local sewage firm and "failing to fulfil its duty" even after it was issued with a warning, the SPP said Monday in a statement.

The lawsuit comes after an investigation by Qingyun County People's Procuratorate into the sewage company over allegations that it lacked adequate environmental protection facilities, it said.

According to the SPP, despite residents' ire and pressure from the county-level Communist Party of China committee, the department failed in its capacity of supervisor and imposed only nominal administrative punishments.

The lawsuit was filed on Dec. 16. Details concerning how the department acted illegally were not included in the statement.

China's top legislature in July approved a draft legal document that allowed prosecutors to institute public interest litigation in civil and administrative cases against acts that compromise public rights and interests by pollution or food and drug safety.