Delhi high court today sought an explanation from Veteran Congress leader N D Tiwari by Monday as to why he was bent upon defying court's order to give his blood sample for a DNA test to decide the paternity suit of a 31-year-old man claiming to be his biological son.

"You (counsel for Tiwari) please take instructions from your client as to why he is not willing to comply with the court order asking him to give blood sample for the DNA test by next Monday," Justice Gita Mittal said.

Justice Mittal sought to know Tiwari's reason for not giving his blood sample for a DNA test, saying that he cannot be allowed to frustrate the court's order.

"We will not allow you to frustrate the order. Let's not allow the impression to gather momentum that you can flout the court orders in this manner," she said.

Justice Mittal was hearing two applications of Rohit Shekhar, seeking prosecution of the 85-year-old Congress leader for non-compliance of the high court order, duly endorsed by the Supreme Court, asking him to give his blood sample to ascertain Rohit's claim of being his biological son.

"The issue of conduct of DNA test can be decided later but first of all you provide the blood sample before the crucial evidence vanishes," the court said.

Rohit had yesterday moved the court for initiation of contempt proceedings against Tiwari after he steadfastly refused to give his blood sample for his DNA test.