Joslin was last seen in east London and also has a previous connection with Kent, but he may have travelled anywhere in the country.
Joslin is a white male, 6ft 1ins tall and of slim build; he is known to use a number of aliases.
He has previously targeted young women and girls and is considered to be a risk to both.
If Joslin is seen do not approach him but call 999 immediately.
Anyone with any information is asked to call police on 101 or contact via Twitter @MetCC. Please quote 3602/17FEB.
To give information anonymously contact Crimestoppers on 0800 555 111 or online at crimestoppers-uk.org.