The Delhi High Court today directed veteran Congress leader N D Tiwari to undergo a DNA test to ascertain the veracity of a young man's claim that he is his biological son. Justice S Ravindra Bhat said, there is imminent need for him to give blood sample to conduct the scientific test. The court turned down the 85-year-old former Andhra Pradesh Governor's plea that he cannot be forced to undergo the DNA test, saying it is the right of a child to know his or her biological father. Justice Bhat passed the order on a paternity suit filed by 31-year-old Rohit Shekhar, claiming to be biological son of Tiwari.