While Singh refused to meet media, sources close to him said the picture, which came into circulation today, is an old one.
On Twitter, several people commented on the image.
"Union minister Radha Mohan Singh participated in #Swachh Bharat#programme# following BJP principles##," a person said on a Twitter.
"Agriculture Minister Radha Mohan Singh relieving in open, throwing PM Modi's Swachh Bharat (clean India) mission to winds," another person said.
Radha Mohan Singh caught on camera urinating in open. Photo: @ANI_news