(CNN) -- Tips led police to a Milwaukee home where they recovered a nearly 300-year-old violin worth millions that was stolen from an orchestra concertmaster, authorities said Thursday.
The Stradivarius violin, known as the "ex-Lipinski," was found in a suitcase in the attic of the home, police told reporters at a news conference.
The violin appears to have been recovered in good condition, but officials are waiting for an expert to examine the instrument, Mark Niehaus of the Milwaukee Symphony Orchestra said.
The violin, appraised at $5 million, was stolen on January 27 from Frank Almond, the orchestra's concertmaster -- the top first violinist.
Three people have been arrested in connection with the theft but have not been formally charged, authorities said.
Police Chief Edward Flynn described the three as a 36-year-old man, a 41-year-man and a 32-year-old woman, all from Milwaukee.
Stefan Hersh, the man who originally authenticated the instrument for the orchestra, told CNN that law enforcement contacted him to identify the violin.
The orchestra offered a $100,000 reward for the safe return of the instrument.
"We're confident the subjects in custody are the subjects responsible for this," said G.B. Jones, acting special agent in charge with the FBI in Milwaukee.
Almond was walking to his car after a performance when an assailant used a stun gun on him, causing him to drop the instrument. The attacker took the violin and fled to a waiting vehicle, which a second suspect was driving, police said.
According to the symphony, Almond plays on a violin made by Antonio Stradivari from 1715.
Hersh has spoken to Almond since the recovery, saying the musician is understandably relieved. Almond has not yet been reunited with the instrument, according to Hersh.
Stradivari was born in 1644. He set up shop in Cremona, Italy, where he made violins, harps, guitars, violas and cellos. Before his death in 1737, Stradivari is thought to have made more than 1,100 instruments -- of which some 650 remain today.
He is the world's most celebrated violin maker.