In 2000, at a Da Vinci conference, leading scholar Carlo Pedretti proposed that Vasari saved Leonardo's masterpiece just as he had Masaccio's.
The conference prompted Seracini to carry out sophisticated tests that involved the use of laser scanners, X-ray machines, and thermographic and radar equipment.
The only nonfictional living character mentioned in "The Da Vinci Code," Seracini found a Dan Brown-like clue in the wall housing the "Battle of Marciano."
There, on a tiny painted green flag, Vasari wrote: "Cerca, trova - seek and you shall find."
The intriguing traces of paint found behind Vasari's fresco represented "an historic result, a mile stone," according to Renzi.
However, to continue their work, researchers required more sophisticated chemical exams such as tomography by XRD/XRF at the European Synchrotron Radiation Facility, in Grenoble, France.
Renzi recently requested permission from the Italian authorities to resume and bring to completion the research, but a controversy had already sprung up over the intrusive approach.
Cecilia Frosinini, mural paintings section director at the Opificio, immediately resigned in protest from the project.
"It's an ethical question. I'm supposed to protect the artworks, and here there is an invasive intervention on the painting," Frosinini wrote.
Following her reaction, many art historians signed a petition asking to stop the drilling and even questioning the possibility that the fresco was indeed hidden behind Vasari's mural.
"Vasari would have never covered a work by an artist he admired so much in the hope that one day someone would search and find it. You would expect such a hypothesis from Dan Brown, certainly not from art historians," Tomaso Montanari, an art historian at the University Federico II in Naples, said.
This summer, the saga of the lost Da Vinci's fresco took its final twist.
Cristina Acidini, superintendent for the Polo Museale Fiorentino, replied to Renzi by authorizing the endoscopic investigation of a seventh hole in a paint-free area originally identified by the OPD, but ruled out the possibility of carrying out futher holes as requested by the scientific team.
In response, Renzi decided to put the project on hold.
In a highly polemic letter to culture minister Lorenzo Ornaghi, Renzi, now a candidate for Prime Minister in the center left party's primary elections, stated: "if the government is afraid to authorize this restoration, which would be authorized anywhere else at any point of time, we will wait until the government changes."
A few days ago, Acidini gave the go ahead to fill in the six holes in Vasari's fresco and dismantle the scaffoldings.
"This is how it ends, with strokes of stucco and paint, the search for Leonardo's mythical work," the daily La Repubblica wrote.
Photo: Top: A fresco restorer discusses the work on the Leonardo project with Florence mayor Matteo Renzi, as researchers Maurizio Seracini looks on. The comprehensive research effort to locate the lost Leonardo da Vinci painting "The Battle of Anghiari" was led by the National Geographic Society and University of California San Diego's Center of Interdisciplinary Science for Art, Architecture and Archaeology (CISA3), in cooperation with the City of Florence. Credit: photo by Dave Yoder/National Geographic. The Battle of Anghiari Project 2012.
– Middle: A 0.4 inch hole was created after a loose fragment of paint from the Vasari mural was removed by restorers and the surrounding area was secured. The point of entry was located at an existing crack in the Vasari mural. Credit: photo by UCSD. The Battle of Anghiari Project 2012 – Bottom: An endoscopic image of the air gap that was confirmed to exist between the original wall in Palazzo Vecchio's Hall of the 500 and the wall on which the Vasari mural was painted. Credit: photo by UCSD. The Battle of Anghiari Project 2012