Police authorities in Southwest China's Chongqing said follow-up investigations into Zhou Kehua's case will continue after the serial killer was shot dead on Tuesday, as media reports said that Zhou's girlfriend has been put under investigation.

Some media reported Wednesday that a woman named Zhang Guiying, 20, was the notorious killer's girlfriend who discussed criminal plans with Zhou. But the allegation had yet to be confirmed by police authorities as of press time.

China Central Television (CCTV) quoted local police sources as saying that Zhou would call his girlfriend before each robbery and tell her about his plans. The mystery woman is reportedly under interrogation.

An important clue showing Zhou planned to cause more bloodshed in downtown Chongqing was acquired from a phone call between Zhou and Zhang, a Chongqing police officer, who only gave his surname as Wu, told the Global Times Wednesday.

Wu revealed that Zhou had been spotted by a young woman in a shopping mall in Jiangbei district just one day after he gunned down a woman in front of a bank and a railway police officer on August 10.

The woman called the police after identifying the suspicious man as the wanted criminal, and was rewarded 600,000 yuan ($94,252) for the clue, Huang Wei, a deputy director of the Chongqing Municipal Public Security Bureau, announced Tuesday.

Wu said the police will continue their investigations, including a search of the city's Gele Mountain, where Zhou was initially thought to be hiding, for further information.

"Many people are joking that they will hunt for 'treasure' in the mountain as most of the money Zhou robbed has mysteriously disappeared. The case still remains obscure to us," a local resident surnamed Song told the Global Times.

The whereabouts of the money, reportedly more than 550,000 yuan, has become one of the questions the public is most concerned about. CCTV said Zhou spent most of the money on his family, citing local police.

"We need more time for a thorough investigation," said Wu.

Zhou, who had taken 10 innocent lives since 2004, was shot to death by two police officers in Tongjiaqiao, Shapingba district at 6:50 am on Tuesday.

Separately, some Web users Wednesday claimed online that another armed robbery took place in Yuzhong district of Chong-

qing, during which a woman was shot and robbed of over 200,000 yuan.

Yuzhong police confirmed this to be a rumor and said they would find the person behind it.