Thank you for your kind words. What a distressing situation this is for your sister. She must be devastated for this to happen where she was trusting professionals to act in her best interests.
I fear your sister’s insurance company can rely upon the policy exclusion they have quoted. As such, I suspect this case will end up being a dispute between your sister and her estate agent, with her claiming against them for financial loss.
This is because, on the face of it, your sister has been let down by her estate agent, who appears to have failed in their legal duty to take reasonable steps to protect her property during any house viewing they are responsible for.
But there are other legal strands to pick up and examine first. If the jewellery was taken by a third party during a house viewing, then as you say, this is a criminal offence, namely theft – not “burglary”, which arises upon illegal entry of property.
Here, the apparent perpetrator may have been on the premises by lawful permission, but it was an unlawful act to take items without your sister’s permission, so in those circumstances, it is theft.
Like any crime, for there to be a successful prosecution there must be evidence and any individual who is accused may expect the case to be proved “beyond reasonable doubt”. This is the burden of proof for criminal cases.
If you report this matter to the police, you should seek to help the investigation all you can by giving them some evidence on a plate. First produce evidence as to what is actually missing, such as an historic insurance schedule or photographs which act as proof of the jewellery that was there before the alleged incident.
Next, set out a statement detailing your sister’s version of events, including her evidence as to when she last saw her jewellery, when she discovered it was missing, and who has attended her house during the intervening period.
It would also be helpful to confirm she is not aware of forced entry or incidents of any door or windows being left open. In other words, she needs to point the finger (backed by evidence) in such a direction as to give the police no alternative but to investigate and speak to certain individuals.
That said, in reality, unless there is some other evidence that can pin the crime on the family who viewed, or indeed the estate agent staff member concerned, or a “no comment” interview by a person of interest to the investigation, it may make it hard for the criminal case to progress. But I would say you have to try.
Even if a successful criminal prosecution occurs, as satisfying as that would be (never mind important for the rule of law), it may not recompense your sister’s financial loss. Pursuing the estate agents is the most likely way to remedy that.
You can pursue the estate agent whether there is a criminal case (whatever the outcome) or not.
There are two possible routes to claiming against the estate agents. One is under breach of contract. Look at the contract and hopefully it says the estate agents will not cause damage to the property, or similar.
If not, I would say this is an implied term of the contract anyway. Alternatively there is a possible negligence claim in terms of them acting below the duty of care they owed to your sister.