The trafficking of African rhinoceros horn on the black market has surged 30-fold in the past 13 years and is now running "out of control," animal protection advocates said Thursday.

"In 2013, more than 2,000 rhinoceros horns from Africa were trafficked, which is 30 times more than in 2000," Celine Sissler-Bienvenu, director of the International Fund for Animal Welfare (IFAW) for France and French-speaking Africa, told reporters in Paris.

The trafficking is "out of control. Like for ivory, like for products from tigers, these are very organised networks that have a great capacity to adapt to changes," she said.

Demand for rhino horn -- which is made from keratin, the same material as in hair and nails -- has skyrocketed in recent years, largely driven by demand from Asia where the powdered horn is valued for its supposed medicinal properties.

It sells on the black market for as much as $35,000 (28,237 euros) per pound.

Experts say the drive for illicit rhino horn, which is worth as much as cocaine or gold, has caused African rhino numbers to shrink by over 90 percent since 1970.

In addition to traditional avenues for smuggled goods, traffickers now have the Internet, which is "a large supermarket open seven days a week," Sissler-Bienvenu said.

During an investigation of 280 online sales sites operating across 16 countries in early 2014, IFAW found "a total of 33,006 specimens, body parts and products derived from endangered species."

The 9,500 adverts they discovered listed sale prices that collectively hit around 7.8 million euros. At least 32 percent of the ads were for ivory, real or fake.

The extent of endangered species trafficking, which is estimated to net criminal gangs 15 billion euros a year, means "anti-fraud agencies need to work together to muster a proper response," IFAW said.