SHANGHAI, Dec. 21 -- A Chinese express delivery company apologized on Saturday after parcels tainted by toxic chemicals killed one recipient and sickened seven others.

In a case that exposed flawed management inside one of China's fastest-growing industries, a man in east China's Shandong Province died of methyl fluoroacetate poisoning after he accepted shoes delivered by the Shanghai YTO Express in late November, according to the Shandong post bureau.

The bureau said four parcels delivered by the Shanghai-based company were found to be contaminated, and five delivery workers and two recipients were also sickened.

A YTO spokesman said the contamination happened after a package containing the chemical leaked during transport. The package was sent by a chemical plant in central China's Hubei Province, who claimed it was "innoxious."

The spokesman said that before accepting the package, the company staff had performed routine checks "according to company rules."

In a statement issued to media, the company said it would not shun its responsibilities and was cooperating with police in the investigation.

Police are still probing the case.

China's express industry witnessed exponential growth in recent years thanks to surging popularity of e-commerce, but experts said the booming business belied problems like poor service and lax supervision.