Ex-trainee policeman cleared of porn charge

Using the screen name of Mr Turnip, Marco Nogueira, 31, had a series of sexually explicit chats with a girl he knew as "Becky", who was in fact a police investigator.

But the defendant told the court the girl's profile stated she was 16 and that he met her in an adult chat room. As such he believed she was lying when she later told him she was 13.

After hearing the jury return a not guilty verdict, Mr Nogueira said he was "glad it is now all over".

The probationer was arrested just moments before he was due to go on duty at Woolwich Police Station on February 27, 2009.

The arrest related to a link to a video of oral sex he sent to "Becky" – a girl he befriended on the Chatterbox site – in February 2008.

The court heard he frequently posted messages on the site saying he wanted sex with a 16-year-old and told Becky he would "love to train you up sexually".

He told the jury: "It was in an adult environment."