Canadian art historian Bogomila Welsh-Ovcharov's new publication Vincent van Gogh: The Lost Arles Sketchbook (Abrams) was unveiled in Paris on Tuesday. But with all the fanfare, the Van Gogh Museum in Amsterdam was notably not on board with the supposed discovery of some 65 sketches by the famed artist from his pivotal period in the south of France.

Van Gogh scholar Ronald Pickvance wrote a foreword about the sketchbook, claiming: “The most revolutionary discovery in the entire history of Van Gogh’s oeuvre. Not one drawing; not ten, not fifty, but sixty-five drawings.”

An expert on van Gogh, Welsh-Ovcharov says she was contacted in 2013 by a local scholar about the find. She made a detailed analysis of each drawing, connecting them to final works made by van Gogh in Provence. She points out new insights on his last years and masterworks such as The Night Café and The Starry Night.

"The patina is there, the brushwork with the reed pen, the way he executes with such vibrato, with such passion, with such force every individual object in nature — you can't duplicate that," she said to CBC.

The Van Gogh Museum has contested the sketchbook's authenticity, based on a review of high-quality photographs, releasing a statement that says, in part, "...it contains distinctive topographical errors and...its maker based it on discoloured drawings by Van Gogh."

Welsh-Ovcharov's publisher says they will issue a response to the museum's claims later this week, reports CBC.