New Zealand's best-known stamp collector may be $A200,000 out of pocket after he was sold stamps by a person who did not own them.
The Victoria Supreme Court found the stamps, bought by Sir Ron Brierley in August 2013, had not been obtained lawfully from the late art dealer Julian Sterling.
Justice Vickery said Sir Ron was an innocent party, but he will order him to return the stamps to their true owner, Mr Sterling's daughter and sole heir Marilyn Kino.
Sir Ron bought the stamps from Mrs Kino's step-brother, Brian.
Mr Kino said Mr Sterling gave them to him between 2008 and 2010, but Justice Vickery said no evidence supported that claim.
The judge was yet to award any damages.