JINAN - Experts have called for stricter supervision over China's express service industry following a delivery scandal in which 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 private 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 "innocuous."

The spokesman said that before accepting the package, 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 has witnessed exponential growth in recent years thanks to the surging popularity of e-commerce, but experts said the booming business belied problems like poor service and lax supervision.

Netizens questioned why YTO delivered the chemical several times despite an existing ban on transporting it through courier services.

Netizens said the practice either suggests the courier was unaware of what it was carrying or simply turned a blind eye to the risks in the parcel.

"While the industry has seen exponential growth in the past, proper oversight of parcels has been largely ignored," said Qiu Baochang, executive vice president of Beijing Law Association for Consumer Rights and Interests Protection, on Sunday.

"In addition, the low threshold for market access brings unqualified companies and exerts a bad influence on the industry," he said.

Experts from the industry also pointed out that supervision over the industry has been neglected by the government.

"Examinations of the parcels only rely on couriers' due diligence," said Wang Guoli, manager of Lushang Logistics Technology Co., Ltd. "So far, the government can only respond to such incidents passively by tracking down the problem after it occurs."

This type of response can hardly prevent similar problems from happening and may leave potential danger unchecked, Wang added.

According to Qiu, government should enhance law enforcement to better supervise the surging industry.

The State Post Bureau of the People's Republic of China said on Sunday that it will launch a nationwide campaign to ensure diligent examination of parcels.

The Bureau said it will suspend couriers' delivery services or revoke their licenses if they fail to examine parcels for prohibited items.