The portrait believed to be of Mozart. (AFP)

London, March 16: A rare portrait of Wolfgang Amadeus Mozart has been unearthed, which gives a true picture of the famous composer’s looks at the height of his fame.

It shows him in 1783, aged 27, dressed in a red tunic and a ruff, with a wig of grey hair and an elegant but slightly hooked nose.

Until now, the enduring image of Mozart has been largely based on the posthumous 1819 portrait by Barbara Kraft, painted 18 years after his death. But this discovery could help change that.

The picture has been authenticated by Cliff Eisen, a music scholar at King’s College. He described it as “arguably the most important Mozart portrait to be discovered” since the composer’s death in 1791.

Eisen, who is to present his findings to academics at the Royal Musical Association, said: “It is only the fourth known authentic portrait of him from the Vienna years, the period of his greatest professional successes and greatest compositional achievements.” Mozart moved to Vienna in 1781, aged 25.

The oil, which measures 19 inches by 14 inches, was bought by an American collector in 2005 from a descendent of Johann Lorenz Hagenauer, a close friend of the composer’s father Leopold Mozart.

The collector has insured it for £2million (Rs 16 crore). It was probably painted by Joseph Hickel, a painter to the Imperial Court of Austria.

Eisen said there was strong documentary evidence to suggest the subject was Mozart, including a letter he wrote to one of his patrons in September 1782, describing his desire for a “beautiful red coat” that matches the one painted.

Mozart wrote: “I really must have a coat like that, as it’s worth it just for the buttons I’ve been hankering after.”