Image copyright AP Image caption Burke Ramsey and his father John Ramsey were cleared by prosecutors in 2008

The brother of murdered child beauty pageant star JonBenet Ramsey is suing CBS and TV producers for $750m (£612m) after being implicated in her death.

Burke Ramsey said his reputation was ruined after a series called The Case of JonBenet Ramsey suggested he killed his six-year-old sister in 1996.

Mr Ramsey claimed the TV network, production company Critical Content and expert interviewees conspired to defame him for publicity and profit.

The US series was aired in September.

JonBenet Ramsey was found dead in the basement of her family home in Boulder, Colorado, on Boxing Day 1996. She died from a blow to the head and strangulation.

Police have since collected and studied thousands of pieces of evidence but no-one has been charged with the killing and the case remains open.

Burke Ramsey was nine at the time. He and parents John and Patsy were all cleared by prosecutors in 2008 based on DNA evidence. Patsy, herself a one-time pageant queen, died from cancer in 2006.

Media playback is unsupported on your device Media caption Videos of JonBenet Ramsey's performances in beauty pageants opened a window into a subculture of which many Americans had been unaware

The district attorney currently overseeing the case has said it was premature to exonerate the family and has ordered additional tests using new DNA technology.

Burke Ramsey's legal action said he had been "exposed to public hatred, contempt and ridicule" following the series.

He accused CBS of conducting a "sham reinvestigation" of the murder, calling the accusation against him "a compilation of lies, half-truths, manufactured information, and the intentional omission and avoidance of truthful information about the murder of JonBenet Ramsey".

CBS has yet to comment on the legal action but at the time of the broadcast, the network said it stood by the program and "will do so in court" if necessary.

It is the second lawsuit Burke Ramsey has filed over the two-part TV series.

In October, he sued forensic pathologist Dr Werner Spitz, who was featured on the programme and said Burke Ramsey bludgeoned his sister to death.