A rare Michelangelo drawing worth more than $10m has been discovered in the back room of a museum in New York.

The drawing was made in the mid 1500s, according to officials at Manhattan's Cooper-Hewitt National Design Museum.

Such a discovery occurs "once in a museum's lifetime," said Paul Thompson, the museum's director. "It's the stuff of children's story books."

The drawing is of a seven branched candle-holder - often called a menorah - in black chalk on cream coloured paper.

The artwork is unsigned but officials at the museum say they have had it unanimously authenticated by scholars both in the United States and Europe.

It is believed to be one of fewer than 10 Michelangelo works in the United States.

Amazing find

The drawing was spotted by Sir Timothy Clifford, director of the National Galleries of Scotland, while on sabbatical at the Cooper-Hewitt museum in April.

You recognise a Michelangelo as you recognise a friend

Sir Timothy Clifford

"To find a new drawing by Michelangelo is very exciting, but to find a drawing by him of a menorah and, moreover, in New York, is almost incredible," he said.

A specialist in Italian Renaissance art, Mr Clifford spent two weeks sifting through a box of light fixture designs by unknown artists in the museum's newly opened Drue Heinz Study Center, a repository of European and American design.

When he saw the distinctive style of the drawing, Mr Clifford immediately identified it as a Michelangelo, but other experts were more sceptical.

"You recognise a Michelangelo as you recognise a friend," Mr Clifford insisted.

Since then, other Italian Renaissance art scholars in the United States and abroad have unanimously agreed the drawing is a Michelangelo piece.

It was purchased by the museum in 1942 for $60, and its current value is estimated at between $10m and $12m, art dealers said.

It is thought the drawing came to the United States from London, but its history before that remains unknown.

The Cooper-Hewitt museum now intends to put its rare find on display sometime next year.