One of the biggest internet classified ad providers has put a stop to the "adult services" section of its US website.

Apparently this stoppage is in response to criticism from prosecutors that they had become a tool for prostitution.

Last year, the site increased screening of adult ads after authorities in New England, USA claimed a man had killed one woman and attacked two others whom he'd contacted through Craigslist.

The ‘erotic' section remains open outside of the USA.

The ‘adult' or ‘erotic' advertisement's on Craigslist that can be thinly covered as advertisements for a massage, or can be explicit photos and text, demonstrates the complexity of online policing.

Craigslist began as an email newsletter in San Francisco in 1995 before progressing into a hub for free classified ads that now has over 700 local sites worldwide. The company claims it has more than 50 million users in the US alone, competing with large newspapers for classified ads in their circulation areas.

The majority of classified ads on Craigslist can be placed for free. However, ‘adult' ads cost $10 a piece in the USA.