Shell Bell

Hi, just looking for some information for a friend. My friend returned to the UK with her husband for a holiday, however due to ill health my friend has decided to stay in the UK as she could not make the journey back. Her husband has since returned to WA to sell their house etc. We thought that a power of attorney drawn up in the UK would suffice. However, now we are unsure? Does anyone know what legal documents her husband will need to sell their property in her absence, taking into consideration that she is too ill to travel back to Oz? Thanks. Shell