The Royal College of Physicians’ Museum in London has bought a mysterious £78,000 portrait, created by revered 17th century artist Cornelius Johnson in 1637, with grants given by The Art Fund, the MLA/V&A Purchase Grant Fund and the Beecroft Bequest.

College President Professor Ian Gilmore said he was “delighted” with the MLA’s decision, calling the painting “a magnificent addition to our collection.” “Accreditation demonstrates the college’s ability to look after this valuable part of our heritage and makes sure that we can share it with the public at large,” he said. “We are very grateful to those organisations and individuals who made this possible.”

Academics have enjoyed lengthy debate over the identity of the male physician in the painting, portrayed in his study against a backdrop of books by Hippocrates, Vesalius, Galen and Paracelsus.

Dr Karen Hearn, curator of 16th and 17th century art at Tate Britain, named the sitter as distinguished RCP scholar John Bathurst, a view shared by William Schupbach, curator of the Wellcome Collection. “One could reasonably say that it is the finest and most programmatic picture of a 17th century academic physician, proudly displaying his knowledge base,” said Mr Schupbach.

But William Birken, an expert on 17th century physicians, suggested the man may be Dr Lewin Fludd, a similarly eminent practitioner of the era. Three other potential candidates - Sir George Ent, Sir Thomas Sheafe and Dr Baldwin Hamey Jr - have been "tentatively" ruled out.

Art Fund director David Barrie described the painting as “intriguing”. “Johnson’s portrait of a learned physician illustrates the history of the profession,” he said. “We hope to learn even more when the College solves the mystery of the sitter's identity.”

RCP treasurer Sir Richard Thompson said: “Being able to apply for grants due to our new museum status will enable us to save more valuable works of art relevant to medicine and show them more widely to the public."