Have you read David Payne's interviews? 
This is potential hard evidence as it suggests the truth of the kids bath time is being hidden for some reason.
00:44:18 1485 "Okay, and when you finished, I'm just trying to put this in order here, when you actually, when you finished and you went back to the apartment, did you say anything to Gerry about, about the fact that his family were fine' Or''
Reply "Yeah, err yeah, I haven't mentioned this before, but yes, yeah I'd certainly, when we met up I said oh yeah, you know everything's fine there, you know probably along the lines of you know you've got a bit more of a free pass you know you can carry on for a bit longer, Kate's fine without everyone you know all the children are, are happy,
there's no difficulties with bath time or anything so you know, without actually saying all that just conveying to him that you know I don't think you need to err rush back, you've got a free pass for a bit longer.' (DP)
Gerry said, were just absolutely knackered and
Kate was getting them bathed and ready for bed. (FP)
That they bathed the children, the deponent having left at 18H00 for a tennis game only for men. (GM)
They arrived at the apartment around 5:40PM, earlier than usual, because Madeleine was tired, their other friends were at the beach and Gerry had an all-male tennis game at 6:00PM.
At the flat they both bathed the children, and close to 6:00PM Gerry went to the tennis courts, soon after the children had finished their bath. (KM)
Kate had a shower which lasted around 5 minutes.
After showering, at around 6:30/6:40PM and while she was getting dry, she heard somebody knocking at the veranda door.
She wrapped herself in a towel and went to see who it was. This door was closed but not locked as Gerry had left by this door. She confirmed it was David Payne. (KM Sep)
1485 "
But could you remember what Kate was wearing for example''
Reply "
I can't, no.' (DP)
Madeleine and the twins went to bed at around 7.30. They were in their respective beds. The interviewee and her husband stayed in their apartment to relax until 8.30pm.
She took a bath, did her make-up and drank a glass of New Zealand wine with her husband. Just after 8.30pm, the interviewee and her husband, after checking on their children, joined the other adults of the group at the "TAPAS" restaurant. (KM May)
At 19H30, the twins were already in their respective cots and MADELEINE in the bed next to the bedroom door. He does not know if they were asleep but from the silence he presumed that they were. As it was still early
he took a bath, he thinks that KATE had already had one, they talked a little and drank wine or beer. (GM 10 May)
After dinner at 17.00, they would bath the children and get them ready for the night and play with them for a few moments in the recreation area near the tennis courts, always supervised by the parents. (GM 4 May)
At 17h00 the OCEAN CLUB nursery care workers conducted MADELEINE and the other children in creche on the 1st floor of the main reception to [the area] next to the TAPAS, under awnings, where they [the children] had dinner under the supervision of the employees and, at times, with their parents.
The dinner ended at 17h30 the time at which the employee supervision ended and the parents took over watching the children in the play area until 18h30. Following this they returned to the apartment, the deponent opened the main door with his key and, then, the rear door through which KATE and the children entered.
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The hygiene done, the children were put to bed about 19h30, it being that the deponent and KATE left for dinner at the TAPAS at 20h30. Between 19h30 and 20h30 they took a bath and drank wine, Portuguese or New Zealand, and a beer. (GM 10 May)