The Netanya Police chief told the trial of Ronny Ron Monday that Ron had confessed to killing his granddaughter Rose Pizem by the first night of questioning.

Police Commander Ron Gertner told the court that Rose's grandfather told police how he carried out the murder, saying: "The child was sleeping, I placed her inside the bag, closed it with the zipper and threw it in the Yarkon."

Ron, Rose's paternal grandfather and her mother's live-in lover, and Marie-Charlotte Renault, Rose's mother, are being tried for the murder of 4-year old Rose, whose body was found in a suitcase in the Yarkon River last September.

According to Gertner, on the first night of questioning Ron took police officers to the site at the Yarkon River close to where Rose's body was later discovered. Only later did Ron give different versions of the location he placed her, Gertner said.

Gertner added that Ron did not give police any further information on the killing on the first night of questioning.

"We asked him if he has no mercy, how he could drown a girl in that manner if she was still alive," Gertner told the court.

"At a specific stage of the inquiry Ron used a more extreme word - 'I liquidated her, I liquidated her,'" he added.

Gertner said that a separate version of the story given by Ron, in which he admitted to hitting Rose and only later throwing her in the river after discovering that she had died, only emerged later.

Rose was born in Paris in 2004 to Renault, a French Jew with relatives in Israel, and Benjamin Pizem, the child of a French mother and an Israeli father. At the age of one, Rose made her first visit to Israel. That was the first significant encounter Benjamin had ever had with his father, Ron, and the first time Marie had ever met him.