The offences, which occurred in September, involved a man messaging a young teenage girl explicit images before meeting in person in Derbyshire.
It is believed the man, who went by the name of Bryn, may have been living in the greater Manchester area as he arrived on a train from the city when the pair met in Hadfield.
He is described as being around 6ft tall, of medium build, with short blonde hair and a freckle on his left cheek.
He also has a number of distinctive tattoos including the date 19.09.2004 on his right hand near to his knuckles.
Anyone who recognises the description of the man is asked to contact Derbyshire police using any of the below methods, including reference 21*527221.
Facebook – send a private message to /DerbyshireConstabulary
Twitter – direct message the force’s contact centre on @DerPolContact
Website – complete the contact form at www.derbyshire.police.uk/ContactUs
Phone – call 101
You can also anonymously contact Crimestoppers on 0800 555 111.