Police are refusing to rule out the possibility that a journalist stabbed to death on Monday was murdered, possibly due to a recent "gutter oil" scandal.

Li Xiang, a 30-year-old reporter for Luoyang TV, was stabbed 10 times outside the gate of his community as he returned home from a night out with friends at a karaoke bar.

A gatekeeper surnamed Shen recalled hearing a cry of "robber" before hurrying into the street only to find the victim lying on the ground several meters away.

Li's laptop was missing and police say early investigations suggest it was a robbery homicide. However, as he was stabbed so many times, detectives are keeping an open mind to other motives. A reward of 20,000 yuan ($3,000) is being offered for information about the incident.

Media across Henan province, as well as many netizens, have speculated that Li was killed after posting a micro blog on Sept 15 about a suspected underground factory producing illegally recycled kitchen oil, commonly referred to as gutter oil.

Police recently detained 32 people and seized 100 tons of oil in a nationwide crackdown across 14 provinces, including Henan.

However, You Kai, deputy director of the office where Li had worked since 2006, all but dismissed the theory.

He explained Li had shifted from reporting agricultural topics to legal news two months before his death, although his beat rarely involved investigative work, with most reports sourced from the procuratorate and judicial authorities.

Li's last micro blog was also a message originally posted by other media, added You.

Regardless, the stabbing has had caused unease among journalists in the city.

Li's parents declined to comment on Tuesday. However, his colleagues described him as "outgoing, honest" and good at his job. He was said to be preparing to marry in early October.