Salem, who was covering the House of Representatives, was found dead on Thursday, 29 days after he went missing in Abuja.
Police on Friday, paraded a 29-year-old commercial driver, Itoro Clement, suspected to be responsible for the death of the journalist.
Taking to Facebook on Friday evening, Mrs Kuraun expressed doubt about police investigation into her brother’s death.
“I watched the doctored movie by Nigerian police and I laughed. How can you knock someone down, and you will not know the date.” she wrote.