The first witness against Belgium's alleged child killer Marc Dutroux has described how two of the victims had been brainwashed by the accused.
Dutroux's testimony was described as "chilling"
Jean-Marc Connerotte, who led the initial investigation, said the two girls kissed Mr Dutroux when he guided police to the dungeon in his house.
"That shows how much he had conditioned them," said the investigating judge.
Marc Dutroux is accused of kidnapping and repeatedly raping six girls in the 1990s, and killing four of them.
He denies the murder charges and kidnapping the younger girls. But he has admitted kidnapping two teenage girls and raping his captives.
On his first day of testimony on Wednesday, Mr Dutroux blamed his ex-wife for the crimes.
And he admitted building the underground cell in his house to hold kidnapped girls, but said he was acting for a "big crime ring".
Judge Connerotte ordered Mr Dutroux's arrest in August 1996, but was taken off the case in controversial circumstances two months later.
The AFP news agency said he told the court how Sabine Dardenne, then 12, and Laetitia Delhez, then 14, had believed Mr Dutroux's story that he was protecting them from a gang of men who wanted to murder them.
Julie Lejeune, 8, allegedly starved
Melissa Russo, 8, allegedly starved
An Marchal, 17, buried in garden
Eefje Lambrecks, 19, buried in garden
Sabine Dardenne, then aged 12 - survived
Delhez, then aged 14 - survived
When the alleged murderer escorted police to the purpose-built dungeon in his house on 15 August 1996, the girls "didn't want to come out" and tried to hide, thinking their rescuers were members of the supposed gang, Mr Connerotte said.
"They thanked Dutroux. It was absolutely terrible. They kissed him. That shows how much he had conditioned them."
The judge also said police had failed to find the concrete-door cell because Mr Dutroux had shown "a terrifying professionalism" in building it.
"He had built a ventilation system so that smells could escape from above. The [police] dogs couldn't smell the girls."
Judge Connerotte was praised for achieving a breakthrough in the hunt for the missing girls in 1996, when he linked a white van used in the kidnappings to Mr Dutroux.
Marc Dutroux, 47 - unemployed electrician charged with kidnap, rape, murder
Michelle Martin, 44 - Dutroux's ex-wife, charged with conspiracy to kidnap
Michel Nihoul, 62 - businessman charged with kidnapping
Michel Lelievre, 32, charged with kidnapping, rape, drug possession
There was uproar in Belgium when he was taken off the case after attending a dinner in support of the victims.
On Wednesday, the defendant told the court that two policemen took part in the kidnappings of An Marchal, 17, and Eefje Lambrecks, 19, in August 1995.
Reporting from the courtroom, the BBC's Angus Roxburgh says he repeatedly used the word "network" to imply the existence of a paedophile ring that he merely served.
Sabine Dardenne is planning to give evidence against him.
About 500 witnesses are expected to give evidence in the trial, which will probably last until June.