Hi, thanks for your question. My name isXXXXX can answer this for you.
There is nothing that stops them doing as they're doing, but it does seem to be going a step further than perhaps you would usually expect.
You do not have to engage with them in this way, although the more you're seen to cooperate, the more likely they are to agree to pay the claim. That said, even if they refuse, then you do have a right of recourse to the Financial Ombudsman Service (which is informal and free) and he can force the insurer to pay up on a claim.
I think I would just say that you've given them sufficient explanation and made more than reasonable efforts already to ensure that they have what they need. That there is a line and they are seeming to cross it - if they wish to make further enquiries, they can, but you've done enough. Ask them for their final response now on whether the claim will be paid so that you can, if you wish to, refer their decision to the ombudsman. That should sort out a quick reply!
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