The painting "Flora", dating back to about 1520, will be seen outside Russia for the first time after being restored by the State Hermitage Museum. It would be exhibited at the National Gallery here.
Melzi, Leonardo's companion and assistant, was largely responsible for preserving the master's notebooks and drawings for posterity.
"Flora", his exquisite painting in question, depicts the goddess of springtime and flowers - Flora - seated in a leafy grotto sprouting with fern and ivy.
"Flora's exposed breast and the way she tenderly inspects a sprig of aquilegia a symbol of fertility emphasise her role as 'mother of flowers'. On her lap she caresses a spray of jasmine, signifying purity, besides anemones representing rebirth," the London gallery said.
After its restoration, the picture's true colours, including the powerful ultramarine blue, and hidden details have been revealed. "Infrared reflectography has also shown that Melzi ensured anatomical correctness by modelling Flora's naked figure before adding her clothing," it added.
"The female facial type with its downcast look is characteristic of Leonardo's Milanese style, as is the mastery of subtle modulations of tone, known as 'sfumato'," the gallery said of da Vinci's influence on the artwork.
It is the first opportunity to see the painting, together with its details and rich colouring which had been lost for decades under layers of old varnish.
This rare masterpiece by da Vinci's favourite pupil has been loaned by the State Hermitage Museum to the National Gallery.
The Gallery is already showcasing two works by da Vinci "The Virgin of the Rocks" and "The Burlington House Cartoon". Starting June 6, the British Library here will also show "Leonardo da Vinci: A Mind in Motion", that will bring a selection of his notes and drawings together.
The painting is up for a free, month-long display.
( With inputs from IANS )