A previously unseen painting completed by Francis Bacon a few short months before his death was revealed on Tuesday (23 February).

‘Study of a Bull’ (1991) has been held in what art historian Martin Harrison describes as a “very private, private collection” in London. It has never before been exhibited, reproduced or even documented.

Harrison discovered the work only a mile and a half from where he lived in London while editing a Bacon catalogue raisonné. The catalogue is the culmination of 10 years of work and will reproduce more than 100 previously unseen paintings by the artist.

According to Harrison, a great deal of detective work was required to prepare the catalogue of 584 paintings. “Art doesn’t come into it really, watching Sherlock Holmes is the only help … you have to find the paintings,” he said.

The catalogue’s publication is scheduled to coincide with the anniversary of Bacon’s death in Madrid on 28 April 1992 at the age of 82.

Harrison believes the two-metre-high study, which depicts a bull against a black and white void is representative of the artist’s demise:

“Bacon is ready to sign off… He knew exactly what he was doing here. Is the bull making an entrance? Is he receding to somewhere else? To his cremation?”

The work incorporates real dust taken from Bacon’s South Kensington studio, a feature which Harrison describes as “terribly poignant”:

“He often used to say: ‘Dust is eternal, after all we all return to dust’.”

‘Study of a Bull’ is due to be exhibited at the Grimaldi Forum in Monaco from 2 July – 4 September 2016. The show, ‘Francis Bacon, Monaco and French Culture’, will also feature Bacon’s first known work ‘Watercolour’ (1929) bought by Lebanese-born businessman Majid Boustany at Christie’s in 2013 for £183,000.