Is my friends ex illegally harassing her?

[twentytwentyfour2024]

Hi my friends ex has LOTS of screenshots of her admitting to texting other men hours after they split and also admitting to doing sexual things on the internet when she was single. He also has her admitting to a lot of other intimate things. She got a DNA test when she had a baby to this ex because he wasn't interested in the baby so she thought this would put his paranoia to bed and help them bond (he suggested and demanded the DNA test so she agreed for the reasons I just mentioned). He is now saying to her dad he needed the DNA to prove the child was his! He has sent her dad lots of messages telling him his daughter is a whore basically and is threatening to send all the things he has on her like the voice note of admitting to doing sexual things online etc. what should she do! Is this illegal??

Yes, it's illegal. Your friend should screenshot all his messages to her and his dad asap and report to police asap. Tell her to tell her dad not to delete any of the messages to him.

What is the law against it?

https://www.legislation.gov.uk/ukpga/2003/42/section/66B

Yes, tell the police straight away. Show evidence of the stuff he's sent the dad or anyone else. It's classed as harassment and possibly revenge porn. I hope your friend knows that having consensual sex with people in person/ online is nothing to be ashamed of. The man in question is the disgusting one. If her dad is a decent man he will try and protect her, not judge her on personal things this horrible guy has tried to release.
He needs to be punished. Repulsive behaviour.

Yes its illegal. What he is doing is harassment. Using a computer could make it a malicious communication. The police can seize his devices.

''Cyberstalking is described as a threatening behaviour or unwanted advances directed at another, using forms of online communications.''
I'm not sure if it counts as coercive control since they are no longer in a relationship, but it could be blackmail or extortion.

https://www.cps.gov.uk/legal-guidance/stalking-or-harassment

It’s a fairly new law but she really much report to the police

Not important in light of the crime but the things what you say about the DNA she had a DNA test done because he was paranoid he wasn’t interested because he didn’t think it was his

She got a DNA test when she had a baby to this ex because he wasn't interested in the baby so she thought this would put his paranoia to bed and help them bond (he suggested and demanded the DNA test so she agreed for the reasons I just mentioned). He is now saying to her dad he needed the DNA to prove the child was his!

Sorry my post was jumbled too !