Unpopular opinion perhaps, but piecing together the little bits and pieces we have, and not hearing anything too horrific yet, I think this may turn out to be something of a storm in a teacup. Even the police have just confirmed that they are not currently investigating and have only liaised with the BBC over video conference. They don't exactly sound in any rush to arrest anyone.
At the end of the day, he is allowed to buy photos from people on OnlyFans, assuming they were verified as age-appropriate, he is allowed to talk to adults in a sexual way. I'm not hearing anything too horrific yet, beyond what people are saying on here: a lot of this sounds like over-egging the pudding to me. Some people have already assumed grooming is going on, but there's no evidence of that. The only scandal may be that we wouldn't expect this person to be like this in private.
He hasn't been accused of encouraging or starting the guy off on drugs. The mother just wants to cut off the money supply because her kid happens to be using that money for drugs. Perhaps the kid has been bribing the older man. I agree with people that it seems strange the mother went to the BBC first and didn't want an investigation but for the older man to just stop giving money to her kid. Hardly screams Savile the Sequel.
Again, this is my POV based on what has come out or seems likely at this stage. It could change when more comes out.