A national lawmaker has urged strict legal supervision for China's milk industry, suggesting that those "black sheep" in the sector should be sent to prison.

Zong Qinghou, a beverage magnate and also a deputy to the National People's Congress, or the country's top legislature, made the remarks after at least 25 people have been detained by Hong Kong authorities for violating a newly-adopted purchase ban on baby formula.

"Personally, I do not quite understand the new regulation of Hong Kong," said Zong, who is in Beijing to attend the upcoming annual legislative session. "But taking Hong Kong as a mirror, we can see the inadequacy of lawmaking and law-enforcement in food safety on the Chinese mainland."

Beginning Friday, people leaving Hong Kong can take no more than two tins of infant milk formula with them.

Violators could face a fine of 500,000 Hong Kong dollars, or 64,500 US dollars, and even prison terms of up to two years.

The new rule was implemented following a severe shortage of some popular brands of baby formula in the city's retail market recently, largely due to surging demand of buyers from the mainland.

"Since Hong Kong can jail those buyers of baby formula milk, why can't the mainland authorities adopt strict laws in this regard and send those black sheep to prison?" Zong said.

Authorities have declared that 99 percent of baby formula milk on the mainland meets relevant quality standards.

"Yet, so many people still rush to purchase milk powder from overseas, which shows that they still lack confidence in mainland's milk industry," said another national lawmaker Peng Weiping from east China's Anhui Province.

A food safety scandal hit the mainland in 2008, when the melamine-tainted baby formula caused the deaths of at least six infants and sickened 300,000 others.

Zong said he went to Australia many times last year to look for a suitable grazing land.

"I have not closed a deal. But I really hope to buy a livestock farm and raise milk cow there to guarantee the safety of milk powder from the source," he said.

Zong said legal supervision is the most fundamental way to rebuild the public's confidence in the mainland's milk industry.

"We should let the lawbreakers pay a heavy price, but not the buyers instead," he added.