Image caption Mr Morton said the case should be a 'wake-up call'

Authorities in the United States have arrested 12 people in connection with a people-trafficking prostitution ring.

Another 44 people have been detained. Eleven women from Central America and Mexico, most in their 20s, were freed.

The women were reportedly forced to have sex with up to 30 men a day, charging $30 (£19) for each act.

The gang is thought to have been smuggling women since 2008, moving them to different cities every week in the south-eastern US.

The US authorities have indicted eight men and four women. Most of the other detainees are said to be clients.

The sex-trafficking ring served mostly ethnic Latino immigrants in larger cities and rural communities of Florida, Georgia and the Carolinas, the authorities said.

One of the indicted, a Mexican citizen, is accused of having threatened to send one woman back to Mexico if she did not have sex with at least 25 men a day.

Immigration and Customs Enforcement Director John Morton said 967 arrests in connection with people trafficking and sex tourism were made last year alone.

"To those who would believe that sex trafficking doesn't happen in America, reflect on this case and think again," Mr Morton said at a news briefing.

Most of the 44 detainees were reportedly non-Americans and would face court action. Those who were illegal in the country would be deported, said Mr Morton.

The scale of human trafficking in the US is hard to gauge, but the National Human Trafficking Resource Center hotline, operated by Polaris Project since December 2007, has received more than 57,000 calls from every state in the union.

Incidences of sex and labour trafficking have been reported in all 50 states in the US, and the District of Columbia, in the two years leading up to 2012.