Thieves have made off with $45,000 worth of new iPhones in a robbery police believe involved a group working nationally.

Police say four men entered the JB Hi Fi store at suburban Modbury in Adelaide last Sunday and while two distracted staff the other two broke into a locked cupboard and stole 51 iPhones.

The theft wasn’t noticed until the men had left the store.

A police spokesman said it was thought the group had been targeting electronic devices at large stores and shopping complexes across Australia.

AAP