The Wicked Cousin

First published as The Saint In Hollywood in The American Magazine (Oct. 1936) then in 3 issues of The Saint Detective Magazine (AUS - Apr. 1955, US - May 1955 & UK - Jun. 1955) and The Saint Mystery Magazine (UK - Jun. 1961) with the current title. Also published in the collections The Happy Highwayman, The Saint Two In One, and The Saint At Large, Alfred Hitchcock's Daring Detective (1969 hardback only) and The Second Saint Omnibus.
A will may or may not have been tampered with leaving a friend of the Saint with little. The Saint thinks he should investigate.