The BKA/prosecutors would have a media liaison function which controls what and when information is released to the public.
Reporters would get snippets from police doing the searches but most information from the investigation is part of a communication plan.
The Sun/C4 documentary was released two to three weeks before the new searches were announced. Look at this strategy retrospectively and:
1. The person/s they are trying to reach are in the UK and they are likely not tertiary qualified - The Sun gives them the most exposure to this audience.
2. This person/s knows CB moderately well and may be withholding information out of loyalty or friendship. They think this person is interested in the case enough to review the detail. They want this person to know that CB is a bad person, a rapist and a paedophile - the scar image, the toys, the kids swimming costumes etc.
3. Considering the above, the person the are trying to get a message to is likely a female, a mother and has perhaps been romantically involved with CB.
I don’t buy into the haphazard accidental releasing of information. IMO, it’s all planned.