Derbyshire Police would like to speak to a man in connection with several thefts of catalytic converters at Chesterfield Royal Hospital.
Five cars have been targeted at car parks on the hospital site in the last three weeks, all during daylight hours.
On one occasion, a Toyota Prius was targeted sometime between 8am and noon on Wednesday, August 21.
Anyone with information is asked to contact the police, quoting reference number 19000444127 and the name of the officer in the case, PC Ryan Gill.
You can send a private message to /DerbyshireConstabulary on Facebook, direct message the contact centre on @DerPolContact on Twitter, complete the online contact form at www.derbyshire.police.uk/Contact-Us or call 101.
You can also call Crimestoppers anonymously on 0800 555 111.