A man who claims he is campaigning to find out what happened to Madeleine McCann has been convicted of contempt of court at the High Court in London.
Tony Bennett was found to have breached an earlier court undertaking not to publish allegations linking Madeleine's parents with her disappearance.
Bennett, who is behind the Madeleine Foundation, was given a three-month prison sentence, suspended for a year.
He was also ordered to pay Kate and Gerry McCann's court costs.
Bennett, 65, of Harlow in Essex, was found to have breached on at least 13 occasions the undertaking not to publish allegations linking the couple, from Rothley in Leicestershire, with their daughter's disappearance.
The breaches included letters he wrote to Home Secretary Theresa May and Prime Minister David Cameron, which Bennett posted on the internet.
Mr Justice Tugendhat said the retired solicitor had deliberately flouted the order and that his conduct was so serious that nothing less than a custodial sentence would suffice.
Finding Bennett guilty of contempt of court, the judge said: "I am sure that he intended to allege that the claimants are to be suspected of causing the death of their daughter, and did in fact dispose of her body, lie about what happened and covered up what they had done."
After the hearing, Bennett said: "I'm sorry for the distress I've caused to them - I'm hoping the way forward will result in both of us drawing a line under the situation."
Adrienne Page QC, representing the McCanns, had previously said there was no complaint about Bennett writing the letters.
She said: "The complaint is the publication to the world at large."
Clarence Mitchell, the McCann family spokesman, said: "Kate and Gerry McCann brought these committal proceedings very much as a last resort.
"Mr Bennett has pursued an incessant campaign against them, repeatedly making false accusations against them.
"Concerned for the effect that Mr Bennett's campaign may have on the ongoing search for their daughter and the likelihood of new leads coming forward, the McCanns concluded they had little choice but to seek the court's intervention.
"The McCanns continue to focus their efforts on the ongoing search for their daughter Madeleine."
Madeleine disappeared in May 2007 in Praia da Luz on the Algarve, days before her fourth birthday.
In July 2008 the Portuguese attorney general said there was no evidence linking her parents to any crime.