WUHAN, June 12 -- Two managers of a restaurant in central China's Hubei Province have been arrested by police on suspicion of adding parts of the opium poppy plant to dishes, authorities said Friday.

According to the Procuratorate of Hanyang District, Wuhan City, the local food and drug administration detected main ingredients of poppy seeds including papaverine and narcotine from dishes of a restaurant during routine tests in March.

The two managers of this restaurant allegedly added poppy seeds to dressings of its stewed pots for the purpose of improving taste of dishes and keeping customers coming back for more, said police investigation.

Adding poppy seeds containing morphine to food is prohibited by law. Doctors say they contain only a small amount of alkaloid, but long-term consumption will lead to addiction, damage to the nervous system and induce chronic intoxication.