Stopped paying mortgage and moved out

Hi

My brother in law was recently involved in a serious accident and was unable to live on his own anymore. We temporarily moved into his flat and undertook the mortgage payments (paying into his account, whilst the payments came out). We have now moved out and my brother in laws POA has now stopped payments for the mortgage. This was a few months ago and I notice that nothing has yet happened with regards to the property.

There have been letters sent by utility companies however including one from a debt collecter. This spooked me and I called up and arranged to take over the account again whilst no-one was living there.

Basically the POA just wants rid of the flat now, and I want to remove all liability for bills. What is the best way to go about this? Can we just leave everything and forget about it or is it likely to affect the POA in some way? The utility company did say I could stop the elec/gas supply so this is an option.

Apologies if this is posted in the wrong area but we really do not know what to do.

Thanks