Fahlström art stolen from Baltic

The ink drawing is a part of a piece called "182 improvisations for night music", and was removed from its metal hinges, leaving a gap in the larger work.

The ink-drawing section measures 18cm by 23cm, and police are studying CCTV footage to try to trace the thieves.

Sune Nordgren, the Director of the Baltic Centre, said the drawing is worth very little by itself.

'Return piece'

He said: "The piece that is missing is one out of 182, and it has no real market value.

"It has, of course, an enormous value to the owner, and for all those people in future who would like to see this work completed again.

"We would like to appeal to anyone who has seen or noticed this piece, to see that it comes back to where it belongs."

The Fahlström exhibition at the Baltic ran until 24 November, and was his first solo show in the UK.

The exhibition was also the first change of exhibits to occur since the opening of the Baltic Centre in July.

It included more than 100 paintings, sculptures and film and sound pieces, as well as an extensive interactive section, Fahlström Digital.

The artist's widow, Sharon Avery-Fahlström, who is co-curator of his work, has been told about the theft, which took place in November but has just come to light.

Fahlström was born in Brazil, of Scandinavian parents, and died in 1976 from cancer.