get containing layer of a property?

I am looping through selectedProperties - and need to get each property's containing layer.

The scripting guide mentions propertyParent and propertyGroup() where they are 0 or null if the parent is a layer. Those won't help me.

So any idea of how I get the layer of a selected property? Its easy if I only allow one layer to be selected. Then I can always assume it's just the selectedLayers[0], but if I have two layers one with to masks and the other one with one mask and I select all three masks I have selectedProperties with three Property/PropertyGroup objects and they will either belong to one of the "containing layers" - can't assume anything in this case

Thanks in advance