Police are continuing to investigate the death of a solicitor from Stockton-on-Tees who had gone out jogging.
56-year-old Peter Thomas Maine, from Wynyard, was found with stab wounds near the running track of the Maiden Castle Sports Centre in Durham.
He was discovered just before 8am on Sunday.
Durham Constabulary said 30 detectives and staff are now working on the case and are keen to speak to anyone who saw Mr Maine that morning.
It emerged that Mr Maine was under investigation for fraud by Durham Police in connection with his job as a lawyer.
The Solicitors Regulation Authority had also launched an investigation into his conduct.
The police are distributing posters with a picture of Mr Maine in the hope it will prompt potential witnesses to come forward.
– Detective Chief Inspector Steve Chapman
"Mr Maine's death remains suspicious but we have to keep an open mind as to how he came by his injuries.
"We have established a major incident room at police headquarters and we are committing the same resources we would for any homicide investigation."