SPANISH police investigating the deaths of five Chinese restaurant workers have launched a major manhunt for a waiter who was believed to have been having an affair with the murdered owner of the establishment. An arrest warrant was issued last week for the 19-year-old man, whose name has not been released but who has been identified as the nephew of the chef. According to police, the suspect arrived in Spain after serving a three-year jail term in China, although they did not reveal details of where he came from, what crime he committed or whether he entered the country illegally. The body of the 40-year-old owner, Cao May-ying, was found by her brother in the Ciudad de Mar restaurant, in Gandia, near Valencia, on January 2. The four other victims - three waiters and a waitress, 36-year-old Gong Su-li - were found hacked to death in a nearby second floor flat which they shared. Three bodies were piled in a bathtub, while the fourth was found in the living room. All are believed to have been killed at the end of December, possibly on the 28th. Detectives said the victims had been tortured before being chopped to death with an axe, and that the bodies of two of the dead, believed to be Cao and the chef, had been mutilated. Police have not ruled out a Chinese underworld link to the murders. According to a witness, the restaurant had been broken into and wrecked six months ago, possibly as a warning to the owner. After the bodies were discovered, detectives said they believed the murders were linked to a Chinese gang involved in extortion and the smuggling of illegal immigrants. Minister of the Interior Antoni Asuncion said the investigating team had ''two good clues'' as to who committed the murders, although he did not elaborate. Meanwhile, police now believe the murder of a Chinese businessman in the northeast of the country is not connected to the murders in Gandia. The body of Michael Ye, 21, was found on New Year's Eve in Gava, in Barcelona province, although detectives said he had been dead for three days. He had been stabbed 15 times in what police believed was a gangland killing.