Father of three Jay Kaycappa faces two charges of common assault for this and a further alleged incident the following day after he had been sent to photograph Mills McCartney in her home town of Brighton last year.

If found guilty, Kaycappa faces up to six months imprisonment on each charge.

The prosecution alleges that Kaycappa assaulted Mills-McCartney in a subway by “janking” her shoulder to turn her round. Kaycappa denies both charges.

The court heard that Kaycappa had been commissioned to follow Mills McCartney for several days in June last year while on shifts for a national newspaper and a regional press agency. Giving evidence in court, Lady Mills McCartney alleged she was regularly followed by a group of up to 25 photographers in the months following her public split from former Beatle Paul McCartney.

In a statement to police, Mills McCartney alleged that while on a bike ride with two friends and her personal trainer in Brighton on 5th July 2006, she had been followed and photographed by three photographers.

“Trapped animal”

Mills McCartney then told the court that in order to avoid the photographers after becoming separated from her friends, she headed into a subway near the seafront, but found there was already a photographer waiting at the other entrance to the subway.

“I panicked and thought ‘I’ll go back the other way’”, she told the court. “That’s when I turned round and saw Mr Kaycappa”.

“I felt like a trapped animal so I turned into the wall to get on my phone”, said Lady Mills McCartney. She told the court that she had phoned “personal trainer and right-hand man” Benjamin Amigoni to “rescue” her.

She alleged at this point Kaycappa ran in to the tunnel, and placed his hand on her right shoulder and attempted to physically turn her round in order to photograph her.

The 39 year old told the court: “I felt a hand on my shoulder. He yanked me round. He hauled me round because I wasn’t letting him get that picture.”

The court also heard that the alleged assault had left her with lasting damage to a vertebra requiring continuing treatment from a chiropractor.

Amigoni, 23, told the court that he witnessed the alleged assault as he was coming into the subway. However, he claimed in court that he had made a mistake in his police statement in which he had stated that it was Mills-McCartney’s left shoulder, rather than her right, which was pulled.

Stephen Lawrence, the photographer positioned at the other end of the subway, told the court he did not see Kaycappa commit an assault.

Kaycappa was arrested by police three days after the alleged attack.

“If the timecodes are accurate, you have lied”

The court was shown a twelve minute slideshow of Kaycappa’s 181 original digital camera files, all of which carried a sequential serial number, and specific date and time stamps of when the pictures were taken.

The photographs showed Mills McCartney entering the subway at 12.45pm, followed by her making a telephone call, throwing her bottle of water over the second photographer and walking her bicycle out of the subway entrance two minutes later, but there was no evidence of the alleged assault.

The prosecution alleged that Mills McCartney was assaulted by Kaycappa during a four second gap in the sequence, but the defence has disputed whether it would have been possible to carry out the assault in that time.

In court, defence solicitor Anya Lewis put to Mills McCartney: “If the times in the photographs are accurate, you have lied.”

Mills McCartney denied this, telling the court that “someone had changed the time codes on those pictures”

She was then asked again by Lewis: “You have given evidence under oath. Are you sure the evidence you have given is a truthful account?” She replied: “Yes”

“Pack of animals”

Martin Bloomfield of Sussex Police Imaging Laboratory Services, who appeared as a witness for the prosecution, said that while it was possible to manually change date and time metadata in a photograph, he agreed that the date and time data on Mr Kaycappa’s images appeared to be accurate.

While the defence believes that the photograph timings prove that Kaycappa did not have time to make the assault, the prosecution put it to Kaycappa that the reason for the four second gap is that he made the alleged assault in that time period.

Prosecutor Dale Sullivan told Kaycappa: “It would be impossible to take photographs while you were grabbing this lady’s shoulder and hauling her round”. He accused the photographers present of hunting McCartney-Mills “like a pack of animals”

The photographs also appeared to show Ms Mills-McCartney leaving the subway by the south exit, whereas she had told the court that she had been forced to leave by the north exit to escape Kaycappa.

Defence solicitor Anya Lewis said: “I suggest that at no stage did you cycle frantically out of the north end of the tunnel.”

Ms Mills-McCartney replied: “I know you’re doing your job but you’re wrong.”

“Question of credibility”

Kaycappa also denies the second charge of assaulting Mills-McCartney’s friend Michael Payne the following evening. He told the court he was only trying to defend himself when the alleged attack occurred, and that any contact was accidental.

In court, Mills McCartney alleged she was making a stand on behalf of other celebrities, including Kate Moss, who had been followed by paparazzi.

“Jay Kaycappa has assaulted a lot of people and upset people and I’m going out on a limb”, she told the court.

It was revealed on Tuesday that Kaycappa has 132 previous convictions for offences dating back 17 years including 62 convictions for fraud, as well as others including theft, burglary, destruction of a will, perverting the course of justice, obtaining property by deception, driving offences and misuse of a computer to disseminate a bomb threat. The court also heard that in the past Kaycappa has been known by ten aliases and has used six different dates of birth.

Prosecutor Dale Sullivan told the court : “The issue in this case is clearly one of credibility. We have to assess on one hand the evidence, demeanour and credibility of Ms Mills McCartney and on the other hand Mr Kaycappa.”

The trial, which was originally scheduled to last just one day, will enter its fifth day when it continues next week.