an expensive gold watch has been found and the owner has still to be traced, can they take out an insurance contract that would be valid in English law
I think what the OP might mean is, someone has found an expensive item. Can that person insure the item against loss, theft or damage until the owner is traced, as strictly speaking it's not his property.
I would add that presumably this watch has been handed over to the police and it is in their safe keeping until it is claimed by the owner , or if not claimed it will be given to the finder.
At this time the finder cannot insure the watch as it does not belong to him/her,and there is no "Insurable Interest" present.
What insurance? and who wants it?
You can't insure something you do not own.
Has the find been handed over to the police lost property section? if not you can be guilty of 'theft by finding' if you just keep it.
Eddie, that is what some people think, quite wrongly. If you find an item and the owner is not known, and do nothing with it there is no offence of theft by finding. The law states that an offence is only committed if it can be proved that the finder could have taken reasonable steps to trace the owner, and this DOES NOT include taking it to a Police Station