The victim of a horrific sexual assault on a Melbourne beach has called for her attacker to face the consequences of his crime.

It was about 11pm on a Saturday in February last year when the then 31-year-old woman was going for a “beautiful walk” along the foreshore on Beaconsfield Parade, Middle Park, and listening to music through headphones.

“It was getting quite late, but there were a lot of people around,” the woman, who has requested to not be identified, said during a press conference today.

Without any warning, she felt someone jump onto her with full force, initially thinking it was a friend pranking her.

"It's very cruel and selfish," the victim said of the February 4 attack. (Victoria Police) (9NEWS)

Police have released a digital reconstruction and CCTV of the suspect. (Victoria Police) (9NEWS)

“But then the way he squished me… I thought ‘oh no, this is no friend. This is serious’.”

The unknown man forced the woman down into the sand, pinned her down and tried to remove her pants.

“I was fighting, thrashing around…I was doing blood-curdling screams,” she said.

A man on the beach quickly came to the victim’s aid, followed by a woman. The victim said her attacker’s attitude instantly changed once he was confronted by the witnesses.

“He switched from a monster to dropping down to the floor…it was like he completely switched.

“He said ‘I’m so sorry, I do bad things.”

The victim was pinned down onto the sand during the terrifying attack. (9NEWS) (9NEWS)

Middle Park is a popular area for joggers year-round. (9NEWS) (9NEWS)

The offender then fled the scene, and continues to be sought by police.

The victim described the February 4 assault as life-changing, saying “it’s very cruel and selfish”.

“It’s huge. For (the attacker) it was just a fleeting moment, but it will always be with me.

“They stole someone’s beautiful energy.”

Detectives have released a computerised version of the suspect’s face; he is described as being aged between 20 and 30-years-old, about 178cm tall with a medium build, light coloured eyes and light coloured hair.

Investigations into the attack on Beaconsfield Parade, Middle Park, are ongoing. (9NEWS) (9NEWS)

“We’re keen to speak to anyone who recognises this man in any way – it could be someone they know or even just someone they have seen in their local area,” Detective Senior Constable Boris DI Camillo said.

The witnesses who came to the aid of the victim are also being sought by investigators.