The Delhi High Court has asked its registrar to take police assistance for bringing veteran Congress leader ND Tiwari to Delhi for taking his blood sample to decide the paternity suit of a man claiming to be his son. Justice Reva Khetrapal yesterday fixed the matter for further hearing on Monday before the Joint Registrar, who in turn will fix the date for collection of the blood sample from Mr Tiwari. The court made it clear that the process of collecting the sample will be initiated within a week after the joint registrar receives the DNA sample kit from Hyderabad-based Centre for DNA Fingerprinting and Diagnostics.