Washington, December 8: A team of researchers has found a rare Michelangelo sketch, probably his last work, in the Vatican archives.

The sketch is said to have been drawn in blood-red chalk in the spring of 1563, less than a year before Michelangelo died at the age 89. It depicts a section the dome of St. Peter's Basilica.

"The sureness in his stroke, the expert hand used to making decisions in front of unfinished stone, leave little doubt: the sketch was drawn by Michelangelo, " Discovery News quoted the Vatican daily L'Osservatore Romano as reporting.

Michelangelo worked as the architect of the basilica for 17 years, from 1547 until shortly before his death in 1564.

It is believed that Michelangelo might have drawn the sketch on the construction site, in order to show stonecutters the shape of the Travertine rock he wanted them to pick up from quarries located in Fiano Romano, north of Rome.

According to the Vatican newspaper, the sketch also contains some measurements such as the numbers 6, 9 and 3/4.

"It talks the language of the stone cutters. Blood-red chalk was widely used among stone cutters and sculptors, as it was easier to recognize the red color on the Travertine rock, " the paper reports.

Michelangelo destroyed many of his designs as he neared death because they were drawn only for a practical use, viz., showing the workers the kind of stone he needed.

Since Michelangelo's drawings were already in great demand at the time, he wanted to prevent their marketing. For the purpose, he had destroyed the sketches as the stone cutters returned from their business trips.

According to the newspaper, the newly discovered sketch survived because a supervisor used the back of the paper to write down the names of some people who had created problems with the stone's transport to Rome.

The paper says that the sketch ended up in files concerning the costs of the basilica's construction, and was discovered only after recent research carried by Rome's Bibliotheca Hertziana and the University of Bonn.

"The discovery is important not only because the sketch is especially rare, but because it shows that a nearing 90-year-old Michelangelo was still in charge of the basilica's work and was taking important decisions, " the paper reported.

The Vatican will present the sketch at a news conference on Monday. (ANI)