I have a very close friend that lost his mother about 8 weeks ago & since then his brother has also passed away, however before he passed away he received some of his mothers belongings, he was in a defacto relationship, have I any rights to ask for these items back.

First its not a good idea to piggyback your question on someone else's thread. This can lead to confusion. You should start a new thread. So I've moved your question to its own thread.

Once the belongings went to the brother, they became his property to do as he wished. If he left no will then the prevailing laws of inheritance apply (ANY question on law needs to include your general locale as laws vary by area.). You can certainly ask but the partner may not be compelled to give them back.

BTW, you start talking about a friend, then ask if "I" can ask for the belongings back. You really do not need to play this asking for a friend game here.

You say you have a close friend, then ask if you have any rights. Do you mean does your friend have any rights? He can and should ask, of course, but if his brother didn't leave a will, he doesn't have a legal claim. His best bet is to plead to the good will of the person who has them. He could try small claims court but may have difficulty convincing the court of what she has and how she got them, and whether the brother intended for family to have them. What total value are they?