SHANGHAI - Police in Shanghai have asked a district procuratorate to approve the arrest of a postgraduate student who allegedly killed his roommate by poisoning him.

The suspect, a man surnamed Lin who attends medical school at Fudan University, held a grudge against his 28-year-old roommate Huang Yang over a trivial matter and planned the poisoning, an initial police investigation showed.

Lin took a deadly chemical compound from a university lab and used it to contaminate a water dispenser in their dormitory at noon on March 31, the investigation showed.

Huang, a third-year medical postgraduate student at Fudan University, showed poisoning symptoms after drinking water from the dispenser on April 1 and was pronounced dead due to multiple organ failure on April 16.