BEIJING - Shenzhen customs officers in South China's Guangdong province detained three people suspected to have smuggled amber worth millions of yuan into the country.

Two Taiwan residents and one mainland manager were detained. The amount of money involved was up to 828 million yuan ($131 million), and the group is suspected of evading customs duties totaling around 120 million yuan, according to a statement given by the General Administration of Customs on Tuesday.

"At present, the three suspects have been transferred to the Shenzhen people's prosecutors office and are awaiting charges," said Tao Yong, a spokesperson from the General Administration of Customs.

The suspects allegedly falsely designated amber as rosin, a less expensive form of hardened resin, in their customs declarations to avoid duties, and they also declared prices at lower rates.

The group allegedly smuggled a total of 232 tons of imported amber materials valued at 828 million yuan.

Amber is resin from tens of millions of years ago that has become fossilized over millennia. It is highly valued for its aesthetic and medicinal value.

In nature, amber is far more rare than rosin, so its prices and taxes are much higher. The combined tax rate on imported rosin is 20.5 percent, while tariffs on amber can go as high as 35 percent, according to customs officials.

In April 2011, while Shenzhen customs officers were on regular patrols at the airport, they became suspicious about a container with irregularities in its paperwork.

The customs declaration said that the unit contained rosin with a declaration unit price of 50 euro per kilo, but the receiving unit was a company in Shenzhen that specialized in processing amber jewelry, Peng Haihong, press officer from Shenzhen customs said.

Through sample examination, anti-smuggling police found the container actually held within it completely processed necklaces and bracelets, and the material from which the jewelry was made appeared to be natural amber, she said.

Through further investigation, Shenzhen customs discovered that from July 2010 to March 2011, the company falsely declared the imported goods as rosin a total of 14 times, according to Peng.

China is country that produces large quantities of rosin each year, and the chemical compositions of amber and rosin are basically the same, but there is a huge gap in the prices.

After acquiring solid evidence in May, 2011, Shenzhen customs sent more than 30 anti-smuggling officers to expand a large-scale crackdown and detained two Taiwan residents, seizing 500 kilograms of amber raw materials.

Meanwhile, the police also detained another suspect surnamed Qiu, the manager of a customs clearance agency in Shenzhen that helped to fabricate some fraudulent contracts and invoices.

The anti-smuggling department of Shenzhen customs confirmed the company had tried to evade tariffs worth millions of yuan by fabricated declarations.

"We will step up efforts to crack down on smuggling, and try our best to examine the declared goods as much as possible, especially the suspicious ones," said Tao Yong.