YANJI, China--Officially, in line with a U.N. Security Council resolution in August, no seafood from North Korea has been sold in China since September.

Unofficially, it's a different story.

In Yanji, in Jilin province's Yanbian Korean Autonomous Prefecture close to the border with North Korea, one outlet in a market displayed a sign advertising fresh seafood from the reclusive country at wholesale prices.

A saleswoman told a customer Dec. 27, "Snow crabs from North Korea. They came in just yesterday."

Snow crabs plucked from a tank were selling for 110 yuan (1,900 yen or $17) per kilogram, about the same price as this time last year. Clams and horsehair crabs said to be from North Korea were also on offer.

In September, soon after the import ban was implemented as part of economic sanctions against Pyongyang for its ballistic missile launches and nuclear tests, crabs sold at the outlet came from Russia--but with a hefty price tag of 400 yuan per kilogram. At that time, sellers explained that seafood from North Korea was not available because of the ban.

Chinese customs statistics since September state that seafood imports from North Korea remain at zero.

Sellers at the outlet would not divulge how the batch of seafood from North Korea was obtained.

However, another operator in the market said, "Produce from North Korea is smuggled in. We cannot sell Russian products because they are just too expensive."

In Hunchun, another community in the autonomous prefecture that is close to the border, a number of seafood wholesalers shut their doors immediately after the ban took effect. However, some have reopened for business, and tanks in their outlets were full of crabs.

One individual who handles North Korean crabs said, "Even if the sanctions continue, there are routes for obtaining the produce."

One Chinese trader who was involved in the smuggling of North Korean seafood said, "Chinese and Russian fishing boats purchase seafood out at sea from North Korean fishing boats and then bring it in, claiming the haul was caught in Chinese or Russian waters."

In some instances, the seafood is obtained by bartering fuel, sugar or alcohol in exchange.

According to Chinese customs statistics, China imported about $45 million (about 5 billion yen) worth of seafood from North Korea in July. That figure represented about 30 percent of all imports from North Korea for that month.

That is one reason the August sanctions targeted seafood imports. The U.N. Security Council syspects that North Korea was using foreign currency obtained from its exports of seafood to pay for development of its ballistic missiles and nuclear tests.

While Beijing implemented the seafood import ban from Aug. 15, the situation in markets in northeastern China shows how difficult it is to clamp down on such trade.