Wanted man Doyle James, aged 27, is believed to hold vital information about incidents of witness intimidation and malicious communications.
He is also wanted for failing to answer bail and breaching bail conditions.
Officers believe he may be in the Intake, Handsworth and Mosborough areas of Sheffield and may be drinking in local pubs.
He also has connections to the West Midlands.
South Yorkshire Police said: “Doyle is believed to be violent and we would urge anyone who knows of his whereabouts to call police or report anonymously through Crimestoppers. The public are advised not to approach him directly.”
Anyone with information should call 101 and quote incident number 483 of January 20.
Crimestoppers can also be contacted, anonymously, on 0800 555 111.