theft between relatives

What case can be filed and evidences needed if a relative (e.g. brother more than 30 years of age) have been taking things (doing theft) from a sibling who is also at a legal age? Both siblings are living in the same house, but with different rooms. The room of the sibling (complainant) is usually being forced open by the brother when no one is around. Things being taken by the brother just recently is more than Php50,000 and getting worse (more expensive) over the years.Is there a way to ban the brother from the house? The parents of the siblings are also amenable in banning the brother who have also been taking things and money from them over the years. The brother is also a known user of illegal drugs and who have already been brought to a drug rehabilitation. The relatives just do not know how to go about the situation in order to protect themselves.