Logan Mwangi's father speaking on ITV's Good Morning Britain
Logan Mwangi's father has said Angharad Williamson messaged him saying he wouldn't see their son again after she started dating her new partner.
Logan, a once "smiling, cheerful little boy", was found dead in the River Ogmore in Bridgend on the morning of July 31, 2021.
He had suffered 56 external cuts and bruises and "catastrophic" internal injuries, which were likened to those seen in a high-velocity car crash.
His mother, Angharad Williamson, and stepfather, John Cole, were jailed for life for his murder at Cardiff Crown Court on Thursday, June 30.
A 14-year-old boy - who can now be named as Craig Mulligan after a judge lifted an anonymity order - was also convicted of Logan's murder and sentenced to 15 years.
Looking at pictures of his son while being interviewed on Good Morning Britain on Tuesday morning (5 July), Logan's biological father, Benjamin Mwangi said: "It's never really going to get easier. Maybe with time, it might be but right now, it really isn't.
"I don't think anyone can find the words to try an explain why any parent could treat their child in that manner."
Ben, who lives in Essex, had not seen Logan for around three years and is now campaigning for a change in the law. He and Angharad Williamson had split up in August 2016.
Speaking to Susanna Reid and Ed Balls on GMB, he said: "Because I hadn't seen Logan for so long, I had absolutely no knowledge or no idea about what was going on.
"When their (Angharad and John Cole) relationship started was the last time I had contact with Logan.
"I'd spoken to him a couple of times on the phone when he visited his grandmother. Other than that, I had no knowledge whatsoever about what was happening to Logan.
"I was prevented from seeing him by her (Angharad) and John Cole. We were co-parenting but as soon as Cole stepped into the scene, everything completely changed.
"He said I was talking to her too much, but obviously we'd only talk about Logan.
"After that, everything just fell apart and she sent me a message saying Logan has a family now, he doesn't need me in his life and that I wasn't going to see him again."
Ben Mwangi says he wasn't told when Logan was put on the child protection register and assigned a social worker.
He is now campaigning to make it a law for estranged parents to be told if their child is under the supervision of social workers.
He said: "This is exactly what Logan's Law is going to be about.
"It's letting estranged parents like myself know when their child is known to social services.
"If I had any inkling that Logan was known, I would've gone and got him. I would've worked with the police and social services and said 'I'm getting my son's things and I'm taking him away from this hostile environment. If he's in danger, let's make him safe.
"Sometimes people do get jealous of ex-partners but if you've got a child with somebody else, it's just going to be inevitable. Co-parenting does have to happen. It's for the best interest of the child."
Logan's body was found partially submerged in the water wearing dinosaur pyjama bottoms and a Spider-Man top, just 250 metres from his home.
Ben added: "One of the hardest things was knowing that Logan had a gap of survivability.
"If he would've had any medical attention, he had an 80% chance of survival. That was probably the hardest part.
"We will never truly know exactly what happened inside Logan’s home when he was killed. We do now know that all three of his murderers had a part to play in a sustained and brutal assault, which ultimately led to his death, and the subsequent cover up.
"One of the things that will always live with me is for Logan's last moments, there was three people in that household who knew exactly what happened to Logan. Now, they're in prison, they'll never tell me, they'll never tell anybody exactly what happened to him."