The Vatican revealed on Thursday the discovery of a design sketch featuring a portion of St. Peter's Basilica its experts believe to have been drawn by master artist Michelangelo.

Created in 1563, the drawing is also believed to be the final sketch the famed artist completed before his death, according to a report in Vatican newspaper l'Osservatore Romano.

Scrawled in red chalk, the paper drawing shows a section of St. Peter's dome and includes various measurements to give direction and guidance to stonecutters working on the basilica's construction.

The paper noted that the very existence of the document is rare because Michelangelo ordered many of his late-life design drawings to be destroyed.

Experts believe that the drawing survived because its reverse side was later used — perhaps by some construction workers — to scribble down further notes and calculations.

Officials discovered the drawing within a set of files about the construction costs of St. Peter's.

Michelangelo worked as an architect at the basilica from 1547 until shortly before his death in 1564.

The drawing will be formally presented at a news conference at the Vatican on Monday.

With files from the Associated Press