Harish Chand Mathur (75) and Yogesh (40) were allegedly offered a poison-laced drink by the accused, Raju, SSP Gulab Singh said.
Both of them were admitted to nearby hospital, where their condition was stated to be serious, he said.
Another man, Vivek (25), who supported one of the two contestants, also consumed the drink and was admitted to a hospital.
Further investigation into the matter is on, police said.