Christopher Jefferies is expected to tell the inquiry how some newspapers destroyed his reputation in a trial-by-media scenario after the murder of landscape architect, Joanna Yeates last December.
And Church will describe how the News of the World ran a story about her father having an affair despite knowing her mother had just attempted suicide.
Meanwhile, the Leveson Inquiry, which is investigating media ethics, has summoned political blogger, Paul Staines, after supposedly confidential evidence emerged online.
Staines, who runs the Order-Order website under the name Guido Fawkes, published a link to papers submitted to lawyers by former Downing Street communications chief Alastair Campbell.
Though Staines claims to have obtained the papers legally.
The appearance of Jefferies and Church comes after a string of alleged victims of media intrusion have testified before Lord
Justice Leveson at the Royal Courts of Justice.
The inquiry has already heard that Church has experienced journalists installing secret cameras in bushes and photographers trying to take pictures up her skirt.
A former teacher, Jefferies is expected to describe how his reputation was left in tatters after police wrongly arrested him over the
Bristol murder of landscape architect Joanna Yeates last December.
TV presenter, Anne Diamond, who has accused the Sun and News of the World (NoW) of continually hounding her, will also give evidence at the inquiry.
Then former Army intelligence officer Ian Hurst and Northern Ireland human rights campaigner Jane Winter, will claim their emails were illegally accessed by private investigators working for the NoW.
The Leveson Inquiry is entering its third week.
