ONE of the four men accused of the savage assault and murder of South African student Hannah Cornelius has plastic pearls embedded in his penis, likely making the rape more painful.

Afrikaans news outlet Die Son reported Geraldo Parsons claimed the piercings were part of his Jewish culture and gave his girlfriend pleasure.

But in other unrelated cases criminals have been accused of inserting similar appendages to inflict pain during sex.

A reporter for News24 tweeted that initial questions about the penis piercings raised objections, which were withdrawn, prompting Parsons to say the pearls were "his privacy".

The horrifying detail is the latest from the case, in which it was revealed yesterday that Cornelius's parents were sent a begging letter by one of the gang rapists who killed her.

The letter was submitted as evidence on Tuesday, after a separate court decision deemed it to be admissible, and asked the parents: "Don't be angry with me, please".

Vernon Witbooi, 33, Geraldo Parsons, 27, Nashville Julius, 29, and Eben Van Nieberk, 28, face a string of charges including murder, kidnap, robbery and rape of the Stellenbosch University student.

The letter was from Eben van Niekerk, who claims it was written at the instruction of Stellenbosch police officer Sergeant Steven Adams.

While it was riddled with spelling and grammatical errors, the letter when translated from Afrikaans read:

"Herewith I write this letter to Henna's mom and dad. I am sorry for what I did and I ask if they can forgive me for what I have done…

"The girl was like a friend to me but the other accused, I was also scared of them and it wasn't nice to see. I was also scared of them. Don't be angry at me please (sic)."

The top of the letter read: "This letter comes from Eben VNK" and it was signed and initialed.

Cornelius was dropping friend Cheslin Marsh home in Stellenbosch, near Cape Town, after a night out when the pair were set upon.

She had parked her blue VW Golf – a gift from her grandmother - outside his flat but as they parked a gang of four men attacked them, opening both doors.

In grainy footage, Cornelius' blue Volkswagen Golf was spotted driving from his block of flats at 3.40am.

The car then appears on another CCTV camera at a petrol station an hour later.

A female figure seen in the front seat is believed to be Ms Cornelius in the last moments she was seen alive.

Also on the CCTV, one of the men accused of her rape and murder is seen exiting the vehicle at a shop and attempting to withdraw money from Marsh's account.

In court previously, one of the four men accused broke down in court as he revealed the final plea she made to her attackers before being killed.

Geraldo Parsons, along with his co-accused, originally pleaded not guilty to the murder of Cornelius, and attempted murder of her friend Cheslin Marsh, 22, near Cape Town last year.

However, the 27-year-old’s story changed when he was called to the witness stand and made an unexpected confession.

Parsons testified that as the group drove a terrified Ms Cornelius to an unknown spot she begged the men not to kill her after they “have sex with her”, according to Times Live.

“While I was driving‚ Vernon gave me a condom‚ I don’t know where he got it from. Vernon said Hannah said we can have sex with her but then we must leave her after that,” a weeping Parsons told the court.

He claimed he was the first to rape Ms Cornelius, before Witbooi and van Niekerk, but “it didn’t feel right” because he had a wife and child.

The accused claimed he told Witbooi to let the woman go afterwards but they put her in the boot of the car and drove her to a nearby vineyard. When they reopened the boot Ms Cornelius allegedly refused to get out, clinging on to the car.

“Eben came up and stabbed her. I let her go as the blood started to spill,” Times Live reported Parsons saying.

“Then I saw Vernon arrive with a rock. I told Vernon “don’t kill her, we’ve already killed Cheslin, let’s leave her”. But Vernon threw the rock on Hannah’s head," Parsons claimed.

“I saw it in her eyes that she was terrified. She said we can have sex but I saw she didn’t want to.”

Friend Cheslin Marsh previously broke down in tears as he told how he was bundled into the boot during the attack, while Cornelius was wedged between two of the four men in the VW Golf, the court heard.

They then drove out of the upmarket wine producing town of Stellenbosch and hauled Marsh into the bushes, the judge was told.

Three men allegedly made him lay his head on a rock on the ground and battered his skull with bricks until they thought he was dead.

When Marsh woke up, suffering severe head injuries and a broken arm, he staggered to a nearby home to raise the alarm about Hannah.

Unknown to him her body had been found earlier several miles away by workers and a huge police search was already underway for him.

Previously, a workman described to a court heard how he initially thought the badly beaten body of the 21-year-old student was a "doll".

Giving evidence, pathologist Deidre Abrahams said she would have died "instantly" from the force of being hit twice on the head.

The 40kg boulder had been used to cover a borehole and was slammed down on her head twice as she was held down, a court was told.

She had also been stabbed in the neck and she showed signs of severe genital injury, reports 9News.

Three of the four accused, Witbooi, Julius and Van Nieberk, admit that they were present but claimed they only robbed the pair and did not commit the rape or murder.

Previously, one of the men accused of the murder of Cornelius had his confession - made the day after his arrest - read to the court.

He said the gang went into town “to see what they could get”.

Witbooi alleged the other three took Marsh out of the boot while he had a “smoke”.

He said they told him they had tied him up and left him to be found.

They were “only after money” and denied any part in Hannah's rape and murder, the court heard.

Witbooi said three others returned from the bushes after raping Hannah and said: “While we were driving Parsons said I had missed out on having had sex with her.

“He said they had tied the girl up and that the workers would find her tomorrow.”

The gang, then high on drugs, allegedly went on a robbery spree in the hijacked car robbing at least three women before the stolen motor was spotted and a high speed police chase began.

Three were arrested after dumping the car and fleeing and the fourth was arrested later.