Olga Borisov, who was arrested on suspicion of drowning her four-year-old son at a Bat Yam beach late Thursday night, will not be released for his funeral on Sunday. The Petah Tikva District Court rejected Borisov's appeal, saying that the 42-year-old could mourn in prison. Nevertheless, the boy's father, Ilan Yehuda, who was released on Saturday on condition that he does not communicate with members of his wife's family, was allowed to attend the funeral. Police suspected that the Yehuda knew his son was in danger. Investigators said that while there were still suspicions against the father, he was released after they were satisfied he could not interfere with the investigation. Borisov was spotted by youths pacing the beach and mumbling that she had drowned her son, Alon. Passersby located the boy in the water and jumped into the sea to pull him out. Paramedics tried to resuscitate the child and then declared him dead. Borisov, from Rishon Lezion, reenacted the drowning for police hours later. She told officers that her actions had been premeditated because her son "was a burden." She was remanded on Friday for four days by the Rishon Lezion Magistrate's Court. She is undergoing a number of psychiatric examinations. Her lawyer, Tali Gutlev, said her client was mentally unstable and had originally planned on committing suicide after drowning Alon. Borisov had apparently changed her mind about committing suicide, as documented in a letter of apology addressed to her husband, Ilan Yehuda, recovered by police from her purse. "I love the boy, but I do not want to die with him," the letter read. Gutlev said her client wanted to attend Alon's funeral. Police are reportedly also looking into suspicions that Borisov deliberately threw her son out of a high-storey window a number of months ago in Russia, breaking his legs. Yehuda's lawyer said his release came after police realized they had erred in arresting him. He said he had returned home from work on Friday and had assumed his wife and son were visiting a friend. As the hours progressed and they did not return, he contacted the police. Yehuda mourned the loss of his son in court on Friday. The presiding judge said evidence showed that he had not wanted any harm to come to his son.