"Our several leaders have time and again told them (Nihang group) in the past one-and- a-half month that this is a farmers' protest and not a religious movement. But even then they remained there," he said in a video message.
Condemning the murder and demanding strict punishment for the perpetrators of the barbaric act, he said that the Samyukt Kisan Morcha (SKM), will fully cooperate and support a legal investigation into the matter.
The victim, identified as Lakhbir Singh, a resident of Punjab's Tarn Taran district, was residing for the past three to four days with the same group of Nihang Sikhs, who brutally killed him, he said.
"We are against sacrilege of any religious text but on this basis no person can be allowed to take law in his own hands," Yadav added.
Earlier on Friday, the body of a man with a hand chopped off was found at the Singhu border, where farmers have been protesting against the three contentious farm laws for the past one year.
It is being alleged that the man was caught while desecrating the Sikh religious holy book, however, an official confirmation about it is still awaited.
As per the images that have surfaced on social media, it is possible that the man was tortured before he was brutally killed, and the incident has sent shockwaves all around.