Who is Mr. Neville St. Clair in the story, The Man with the Twisted Lip, from the collection, The Adventures of Sherlock Holmes?

Mr. Neville St. Clair is a somewhat successful business man, who has taken to disguising himself as a beggar to make more money on the streets of London. Fearing that his wife has found out his secret, he fakes his own disappearance and is then accused of his own murder.