File photo: SAPS (Twitter)

A millionaire businessman’s ex-fiancee broke through a toilet door and attacked his new girlfriend after a boat race, a court heard on Thursday.

Max Walker, 54, was celebrating his third-place finish with Samantha Newby-Vincent, 43, at an exclusive marina when Rebecca Vowles saw them and went on an abusive rampage, calling Miss Newby-Vincent a ‘fat ****’, it is alleged.

The court heard Vowles, 47, then followed her into the toilets and shouted at her through the locked cubicle door.

At that moment Vowles is alleged to have forced the door open and punched Miss Newby-Vincent in the head, leaving a small cut.

Mr Walker came in and pulled his ex off his new partner after receiving a text for help, Poole Magistrates’ Court heard.

The businessman had been engaged to Vowles and proposed to her in 2009 by having the words "will you marry me?" stitched into the sail of his 38ft yacht.

They had a very acrimonious split in August 2012 and he has been with Miss Newby-Vincent since March last year.

Vowles denies the charge of assault by beating Miss Newby-Vincent. Magistrates heard the assault took place at the Salterns Marina Hotel in Poole Harbour, Dorset, after the Poole Bay 100 powerboat race on June 10 last year.

Mr Walker and Miss Newby-Vincent were at the venue, where Vowles is said to have addressed them multiple times in an aggressive manner.

Nicola Peach, prosecuting, said: ‘Miss Newby-Vincent and Mr Walker were at the Salterns Marina Hotel that day and said that Miss Vowles began to shout abusively towards Miss Newby-Vincent earlier in the evening.

"Miss Newby-Vincent goes into the ladies’ toilet, in the cubicle, and locks the door.

"Miss Vowles comes into the toilets, the door flies open and she is punched in the face, which causes a small cut to the left side of her temple."

Miss Newby-Vincent told the court she had never met Vowles before, but knew she was Mr Walker’s ex. She said: "We sat outside with friends. All I heard was Rebecca shouting very abusive words towards me.

"My friends said 'don’t worry Sam, we will look after you'. They made a sort of shield around me so that I couldn’t really hear what was being said. The first time I saw her, I went to my car to get a jacket and as I came back she came round the corner and said 'oh there’s the fat ****'.

"Later, we decided to have some supper. I honestly thought she had left.

"I was about to walk into the ladies’ toilets and I saw her walking through the main entrance of the hotel. I wasn’t sure if she saw me or not but I went straight into the cubicle and locked it for fear she would come in after me.

"I texted Max that I needed him to come get me. I heard a noise outside, then I heard somebody entering the toilets, then my cubicle door being bashed in.

"She hit me in the head. With the weight she pushed the door down, she fell on to me at the same time and I fell over.

"She was shouting at me but I don’t know what. I think there was more than one punch. The next thing I remember she was pulled out of the toilets. It was only later I realised it was Max that pulled her off me."

Harvey Withecombe, a court-appointed advocate for Vowles, suggested the defendant stood by the basins and was grabbed by Mr Walker before she got close to the victim.

But Miss Newby-Vincent replied: "That’s not true at all. I was locked in a cubicle and she bashed the door down.’

The trial was adjourned and will resume on February 4. Vowles has been released on bail.

Daily Mail