Dead cat found in bathroom of murdered Chinese couple at centre of police investigation

Forensic officers made the discovery as they searched the two-bedroom ground-floor flat where Newcastle University graduates Xi Zhou and her boyfriend Zhen Xing Yang were butchered.

The black and white cat was concealed in a bowl of water covered with a towel and kitchen gloves.

Police believe Xi Zhou, left, and Zhen Xing Yang may have known their killer

Police will consult the Chinese community to check if there is any cultural significance or coded message behind its death. In ancient China, cats were regarded as sacred and believed to possess the power to repel evil with a glance.

Miss Zhou and Mr Yang, both 25, suffered multiple injuries and almost certainly knew the killers who subjected them to a targeted and prolonged attack.

Detectives said yesterday that Mr Yang had been tortured for at least an hour before he was knifed.

A post-mortem examination revealed extensive bruising to both forearms which pathologists say was inflicted shortly before the last fatal blows to his head.

Police are considering the possibility that Miss Zhou returned to the flat in Newcastle upon Tyne's West End and disturbed the killers who stabbed her to death in a separate room.

Search: A forensic officer photographs potential evidence

Detective Superintendent Steve Wade said officers are keeping an open mind over the cat's death and forensic tests would establish how it died. But they are considering the possibility that it was killed by those who murdered the couple.

If it scratched an attacker its claws could carry vital DNA evidence.

Detective Superintendent Wade said the bruising to Mr Yang's forearms was likely to have been inflicted as he raised them to protect his head.

'The ageing of the bruising may indicate an assault having occurred an hour or so before the fatal head injuries,' he added.

Mr Yang's body was found in the rear bedroom on Saturday afternoon after three worried friends entered the flat through an insecure window. Miss Zhou, who was known as Ci Ci, was discovered in the front bedroom.

A knife and sharp-edged instrument were used in the attacks, but there were signs that Miss Zhou had also been asphyxiated.

Detectives say she worked as a waitress at a noodle bar in Newcastle city centre but they are 'desperately short' of information about her boyfriend. 

Inquiry: Forensic officers are searching for evidence

He completed an MA in international human resources at Newcastle University in September 2006 and is understood to have been setting up his own business. Miss Zhou finished an MA in applied linguistics at the same time as Mr Yang.

Police are checking the couple's bank accounts for any possible motive behind the killings, but said there was no evidence to suggest the murders were linked to gangs or drugs.