Police investigating the murder of two Chinese graduates in Newcastle have found a drowned cat in the couple's bathroom.
Detectives said forensic examinations were under way into the killing of Xi Zhou and her boyfriend Zhen Xing Yang, both 25, who were found in their flat in the West End of the city on Saturday.
The cat, black with white markings, was found in a bowl filled with water and covered with a towel and gloves. It is undergoing a post-mortem examination.
Detective Superintendent Steve Wade said Mr Yang, also known as Kevin, suffered bruising to his arms up to an hour before he was killed. The injuries were likely to have been inflicted as he tried to protect his head. "He has certainly been subjected to an extensive assault, which has caused significant bruising," Det Supt Wade said.
Mr Yang and Ms Zhou, who was known as Cici and worked as a waitress at the Wagamama restaurant in Newcastle, suffered head injuries caused by a knife and another sharp weapon.
Police have contacted Mr Yang's family in Dalian City, China. They have ruled out any Triad or drug links and have checked the couple's bank accounts. "At this stage we have no motive as to why these two people... should be attacked with such brutality," said Det Supt Wade. "Sometimes the police hold news conferences like this and go through the motions with the media when they already have it in the bag, but this really is an undetected homicide."
An offender-profiling expert is helping the investigation. Police have also checked airport and port passenger lists for suspicious movements since Ms Zhou was last seen on Thursday.