A 30-year-old woman was approached by a man in New Walk, Leicester, at 1.30pm on Monday, September 19 last year.
He offered to get rid of black magic and change her luck before touching her inappropriately when they sat on a grassed area.
Officers have received information that people in Nottingham city centre have been approached in a similar way.
An E-fit of a man police wish to identify and trace in connection with the incident has been released.
The man has been described as Asian, 40 to 50, and about 6ft. He was wearing a turban, dark grey trousers, a tunic and a black coat. Anyone with any information is asked to contact PC 4820 Claire Middleton at Leicestershire Constabulary on 0116 222 2222 or call Crimestoppers on 0800 555 111.