All the photographs were donated to the museum by a couple of collectors.
Conservators had a copy of the painting which had not been altered to base their work on.
Today's revelations point to more major sales on their way in September.
HENI presents four limited-edition prints based on Clarke’s pivotal Vespers series of watercolors. These works are part of a series of prints conceived and completed by the artist in the final months of his life. They are available until August 19.
Ofili's The Holy Virgin Mary sold for a record breaking $4.52m at Christie's in London in June 2015. The painting, which incorporates elephant dung, famously upset then-New York Mayor Rudy Giuliani when shown at the Brooklyn Museum. It is now in MoMA's collection, courtesy of billionaire Steve Cohen.
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