Some useful background to the film, The Last Vermeer. Fascinating film and lots of spoilers for the film below so if you are going to see it, read the rest of it later.

Van Meegeren became a national hero after World War II when it was revealed that he had sold a forged painting to ReichsmarschallHermann Göring during the Nazi occupation of the Netherlands. 

Details from Wikipedia: Han van Meegeren

“During World War II, Göring traded 137 paintings for one of Van Meegeren’s false Vermeers, and it became one of his most prized possessions. Following the war, Van Meegeren was arrested, as officials believed that he had sold Dutch cultural property to the Nazis. Facing a possible death penalty, Van Meegeren confessed to the less serious charge of forgery. He was convicted on falsification and fraud charges on 12 November 1947, after a brief but highly publicised trial, and was sentenced to one year in prison^] He did not serve out his sentence, however; he died 30 December 1947 in the Valerius Clinic in Amsterdam, after two heart attacks. It is estimated that Van Meegeren duped buyers out of the equivalent of more than US$30 million in 1967’s money, including the government of the Netherlands.”

And to the point.

“The trial of Han van Meegeren began on 29 October 1947 in Room 4 of the Regional Court in Amsterdam.^[43] The collaboration charges had been dropped, since the expert panel had found that the supposed Vermeer sold to Hermann Göring had been a forgery and was, therefore, not the cultural property of the Netherlands. Public prosecutor H. A. Wassenbergh brought charges of forgery and fraud and demanded a sentence of two years in prison.^[5]Evidence against Han van Meegeren: a collection of pigments.

“The court commissioned an international group of experts to address the authenticity of Van Meegeren’s paintings. The commission included curators, professors, and doctors from the Netherlands, Belgium, and England, and was led by the director of the chemical laboratory at the Royal Museums of Fine Arts of Belgium, Paul B. Coremans. The commission examined the eight Vermeer and Frans Hals paintings which Van Meegeren had identified as forgeries. With the help of the commission, Dr Coremans was able to determine the chemical composition of van Meegeren’s paints.

“He found that Van Meegeren had prepared the paints by using the phenolformaldehyde resins Bakelite and Albertol as paint hardeners. A bottle with exactly that ingredient had been found in Van Meegeren’s studio. This chemical component was introduced and manufactured in the 20th century, proving that the alleged works by Vermeer and Frans Hals examined by the commission were in fact fabricated by Van Meegeren.

“The commission’s other findings suggested that the dust in the craquelure was too homogeneous to be of natural origin. The matter found in the craquelure appeared to come from India ink, which had accumulated even in areas that natural dirt or dust would never have reached. The paint had become so hard that alcohol, strong acids, and bases did not attack the surface, a clear indication that the surface had not been formed in a natural manner. The craquelure on the surface did not always match that in the ground layer, which would certainly have been the case with a natural craquelure. Thus, the test results obtained by the commission appeared to confirm that the works were forgeries created by Van Meegeren, but their authenticity continued to be debated by some of the experts until 1967 and 1977, when new investigative techniques were used to analyze the paintings (see below).

“On 12 November 1947, the Fourth Chamber of the Amsterdam Regional Court found Han van Meegeren guilty of forgery and fraud, and sentenced him to a minimal one year in prison.”

As for the book and its inscription:

“Van Meegeren played different roles, some of which were shrouded in fraudulent intentions, as he sought to fulfill his goal of besting his critics. His father was said to have once told him, “You are a cheat and always will be.”^[65] He sent a signed copy of his own art book to Adolf Hitler, which turned up in the Reich Chancellery in Berlin complete with an inscription (in German): “To my beloved Führer in grateful tribute, from H. van Meegeren, Laren, North Holland, 1942”. He only admitted the signature was his own, although the entire inscription was by the same hand.^[4][20] (The book by Jonathan Lopez confirmed the accuracy of Jan Spierdijk’s article in De Waarheid in which Spierdijk reported details about Van Meegeren’s book Tekeningen being found in Hitler’s library.“

The film unfortunately follows Kates’s Rule of Movies: the final five or six minutes of a film reverses the sentiment of where the film had been heading, normally to bring on a happy ending where none seemed likely, but in this case, to turn a rogue into a Nazi for no reason whatsoever. Van Meegeren may have been a forger and a criminal as the film portrays him, but there is no evidence that he was a Nazi even if he did try to stay onside with people who would kill him in a second if they knew what he was up to. The film blighted itself unnecessarily. Why turn him into a suspected Nazi sympathiser if an inscription in a book is the only evidence they can find? It sours what should be a fun movie for no point I can think of.