A reward of $500,000 has been offered to help investigators solve a ''heinous'' sexual attack on a woman who was dragged into a North Melbourne laneway before she was bashed, kicked and sexually assaulted five years ago.

Crime Stoppers Victoria have released a rare re-enactment video of the attack in the hopes that the vision may jog the memory of potential witnesses from the night.

This is the first time police have produce a re-enactment in over a decade.

Police believe they are close to making an arrest, but are hoping to hear from four men that Chloe may have spoken to as she made her way north up King Street after her first night out as a new mother, then aged 22.