Four Gozitans, three men and one woman, were yesterday being questioned at police headquarters in Floriana in connection with the murder of Gozitan warden Fortunata Spiteri, who was repeatedly stabbed on August 10 last year while on duty on the road linking Victoria to Gharb.

Police sources said some of those arrested had been held previously in connection with the case. One was arrested soon after the murder.

The sources said all four are aged over 50, and two have been tried separately before for murder. The woman being held is the sister of one of the other three being investigated.

It is being alleged that one of the men, a bus driver, had promised the other three money if they helped him kill the warden, who had apparently ticketed him several times for traffic offences.

Sources said the bus driver took the other three on site but only one of them actually stabbed the warden.

One of the men has admitted his involvement to the police, the sources said.

Police in Gozo have, over the past three days, again scoured the area hoping to find the murder weapon.

One of the men allegedly told police that he had thrown the knife away immediately after the murder. However, it was never found.

One of the more serious difficulties for investigators has been the absence of eyewitnesses, and limited forensic evidence.

Mrs Spiteri died as a result of six stab wounds inflicted by a sharp two-edged dagger.

Investigations are being conducted by Police Commissioner John Rizzo and CID superintendent Pierre Calleja together with Gozo police headed by Superintendent Joe Valletta.