Sanlu Group, the dairy firm first found to be selling melamine-contaminated goods, began receiving complaints of sick children as early as last December, state television said, citing a cabinet probe.
It also said Communist officials in the north Chinese city of Shijiazhuang, where Sanlu is based, delayed referring the matter to higher authorities for more than a month after Sanlu finally told them of the problem on August 2.
'In the eight months from December 2007 to August 2, 2008, Sanlu made no report to relevant authorities in Shijiazhuang and took no corrective measures, allowing the situation to worsen further,' the report on state-run CCTV's news channel said.
'(Sanlu and Shijiazhuang officials) violated rules on reporting major incidents involving food safety,' it added, quoting the cabinet probe.
The report appeared to be the first official confirmation of Chinese media reports that news of the risks posed by the milk products was deliberately suppressed.
Reports of tainted milk only emerged in state-run media earlier this month.
The chemical melamine, normally used in making plastics, was apparently added to milk supplies to give the appearance of higher protein levels.
Although it knew kids were falling ill last December, Sanlu Group did not even begin testing its milk for dangerous substances until June, the cabinet probe reportedly found.
The government has blamed tainted products for four deaths, and said late Sunday that 12,892 children remained hospitalised with kidney problems, 104 of them in serious condition. -- AFP