Veteran Congress leader Karan Singh waded into the row over Chola emperor Raja Raja's religious identity on Friday, asserting that to say the king was a Shaivite and not a Hindu is like saying someone is a Catholic but not a Christian.

More than his monumental achievements and the Brihadishwara temple that he constructed in Tamil Nadu's Thanjavur, which still draws lakhs of devotees annually, the mighty Chola emperor's religious identity has suddenly come into focus.

Tamil filmmaker Vetrimaaran has stoked a controversy, apparently targeting the right-wing forces. He has alleged that Raja Raja Cholan was depicted as a Hindu king and attempts were made to take away Tamil saint-poet Thiruvalluvar's identity as well.

Vetrimaaran has found support from actor and Makkal Needhi Maiam founder Kamal Haasan and Congress parliamentarian S Jothimani. Several pro-Tamil activists have claimed on social media that the Chola kings were Shaivites by faith and this identity of the Tamil kings was "hijacked".

The remarks came days after the release of Mani Ratnam's multi-starrer film Ponniyin Selvan, based on author Kalki Krishnamurthy's historical fiction depicting the story of Arulmozhivarman, who came to be known as Raja Raja Cholan later.

Reacting to the controversy, Singh said he has been astounded to read statements that the great emperor was not a Hindu king.

"This is absolutely ridiculous. Shiva is the primordial Hindu deity, focus of intense devotion for millions over the millennia from Srinagar down to Rameshwaram. The emperor built one of the greatest Shiva temples which are marvels of architecture, specially the great Brihadishwara Temple in Thanjavur, where I have worshipped many times," he said in a statement.

"To say that he was a Shaivite not a Hindu is like saying someone is a Catholic but not a Christian. These semantic gymnastics in a way denigrate and confuse our great religion, and are not acceptable," Singh said.

The word Hindu may have gained traction later, but Shiva and Vishnu, Hanuman and Ganesha, Mahalakshmi and Mahakali have all been part of what we call Sanatan Dharma for millennia, the former Union minister said.

"Let us not again try and create a division between Shaivism, Vaishanavism and Shaktism, the three main streams of the great Hindu religion which has a billion followers around the world," he added.