A reproduction of the painting was created

Spielberg's staff spotted an FBI theft notice last week and realised it was in their employer's collection.

Norman Rockwell's Russian Schoolroom was bought by Spielberg in 1989 from a legitimate dealer, the FBI said.

The painting was stolen in 1973 from an exhibition in Missouri. The FBI estimate the work could be worth $700,000 (£360,000).

Spielberg is co-operating with the FBI and will keep hold of the painting until its "disposition can be determined", the FBI said.

Spielberg's office got in touch with the FBI immediately

The work features a group of children in a classroom with a bust of Vladimir Lenin.

Rockwell is best known for his evocative portrayals of everyday small-town life.

He created many covers for the Saturday Evening Post, the magazine he considered to be the "greatest show window in America".

Rockwell died in 1978 at the age of 84.