The incident took place in Antagarh region this afternoon after arrested Maoist cadre Jagesh Yadav asked for permission to attend the nature's call, Antagarh Sub-Divisional Officer of Police (SDOP) Daulat Ram Porte told PTI.
An accused in several cases of Maoist-related incidents, Jogesh was arrested from his native place Siksod, after which he was being taken to Antagarh police station, the SDOP said.
On the way, Jogesh requested policemen to stop since he wanted to go to the toilet.
He was taken to a hospital in Antagarh and after primary treatment before being shifted to Kanker where his condition is said to be critical, he said.
According to the SDOP, the accused had kept a poisonous substance hidden inside his clothes.
A case has been registered in this connection, he said.