Jurors in the murder trial of a man who threw his four-year-old daughter off Melbourne's West Gate Bridge say they will never be able to reach a unanimous verdict.

During their fourth day of deliberations yesterday, the foreman representing the five men and seven women told Justice Paul Coghlan they would "never agree unanimously on a verdict, no matter how much further time the jury spends on deliberations."

Arthur Phillip Freeman arrives at the Supreme Court for the first day of his trial for the murder of his daughter Darcey. Credit:Jason South

"The jury therefore requests that you direct us how to act in this situation," they asked.

Justice Coghlan said he understood that it was a stressful task but urged them to continue discussions.