More than 130 Chinese companies are involved in the development, production and export of "potentially dangerous law enforcement equipment," up from 28 companies 10 years ago, the London-based human rights group said Tuesday.

"Increasing numbers of Chinese companies are profiting from the trade in tools of torture and repression," said Patrick Wilcken, Amnesty's security trade and human rights researcher.

"This trade, which causes immense suffering, is flourishing because the Chinese authorities have done nothing to stop companies supplying these sickening devices for export or to prevent equipment falling into the hands of known human rights abusers," added Wilcken, the lead author of the 38-page report, compiled with the Britain-based Omega Research Foundation.

One company - the state-owned China Xinxing Import and Export Corporation, which produces thumb cuffs, restraint chairs and electric shock guns - had ties to more than 40 African countries, according to the report.

"While some of the exports are no doubt used in legitimate law enforcement operations, China has also exported equipment that has inhumane effects, or poses a substantial risk of fuelling human rights violations by foreign law enforcement agencies," Amnesty said.

Concerns within China

Wilcken noted that some legal restrictions exist for such equipment being produced and traded in China, but it is often sent to "very unsafe and risky situations" around the world.

"What we've found is that it appears the Chinese authorities do not have a kind of rigorous vetting process in terms of where this equipment is exported to," he added. "They're not doing risk assessments."

The report, titled "China's Trade in Tools of Torture and Repression," noted that the same products are also used by police and other security personnel in China, where "torture and ill-treatment remain widespread."

Exports to Africa

China exported large amounts of "anti-riot equipment" to Uganda in 2011, the report said, "despite concerns that torture and ill treatment by police was widespread in the country."

Similar equipment shipped to the Democratic Republic of the Congo during the 2011 election was used to suppress dissent, Amnesty said. Violence stemming from the vote left at least 33 people dead and 83 injured.

Amnesty said equipment is also being shipped to Cambodia, Nepal, Congo, Egypt, Ghana, Madagascar, and Senegal.

China is a major investor in Africa. The government said in July more than half of its $14 billion (11 billion euros) in foreign aid from 2010 to 2012 went to the resource-rich continent.

dr/lw (AFP, Reuters, AP, dpa)