"Since Arthur Conan Doyle published the first adventure of Sherlock Holmes, "A Study in Scarlet" in November 1887, the public demonstrated enormous enthusiasm, demanding the immediate publication of new adventures of what would become the greatest detective of all time. Conan Doyle would even become Sir Arthur. Faced with the growing success of the character, a Berlin publisher decided to create a series of magazines offering the apocryphal adventures of Sherlock Holmes and the first issue was published January 16, 1907. At this point, the real Sherlock Holmes was the subject of three novels, thirty six short stories and two theatre plays, but the German publisher, ignoring all the (early) copyright laws, published these new adventures without the least permission, written very quickly by some German hacks, but beautifully illustrated by Alfred Roloff. Nevertheless, a sizeable change appeared in the stories: Doctor watson was replaced by a young pupil, Harry Taxon. On October 15 of the same year the French publisher Fernand Laven would publish in France the first installment of "Les Dossiers Secrets de Sherlock Holmes" (The Secret Files of Sherlock Holmes)."
-- in "Les Maitres du Mystère - De Nick Carter àSherlock Holmes, 1907-1914", by Philippe Mellot
In France, the publishers of Sherlock Holmes reacted very quickly and demanded that publication would cease. They only managed to prevent the name "Sherlock Holmes" from appearing on the cover. The first three issues, already printed, were recalled and the covers changed, becoming "Les Dossiers Secrets du Roi des Détectives" (The Secret Files of the King of Detectives). The German copyright holders took a bit longer and the series would go on to have 230 issues, with the name changed from issue 10 on. In spite of the title changes, the famous detective was easily recognizable (he was still called Sherlock Holmes inside) and the series would be translated into numerous languages. We know of Italian, Spanish, Norwegian, Danish, Swedish, Dutch, Turquish and Russian editions.
These issues are from the Portuguese edition, by "A Novella Popular", and are titled "Aventuras Extraordinarias d'um Policia Secreta" (The Extraordinary Adventures of a Secret Policeman), #6 dated April 1st 1909, #15 dated August 10th of the same year, #18 is undated and #105 is dated June 11th, 1911. We seem to have played it safe and the Sherlock Holmes name is not on the cover...