Section 109(1) in The Karnataka Prohibition Act, 1961
(1)Where in the investigation of an offence under this Act, any Prohibition Officer duly empowered in this behalf by the State Government or any Police Officer, not below the rank of a Head Constable has reasonable ground for believing that a person has consumed an intoxicant and that for the purpose of establishing that he has consumed an intoxicant or for the procuring of evidence thereof, it is necessary that his body be medically examined, or that his blood be collected for being tested for determining the percentage of alcohol therein, such Prohibition Officer or Police Officer may produce such person before a registered medical practitioner, (authorised by general or special order by the State Government in this behalf) for the purpose of such medical examination or collection of blood, and request such registered medical practitioner to furnish a certificate on his finding whether such person has consumed any intoxicant, and to forward the blood collected by him for test to the Chemical Examiner or Assistant Chemical Examiner to Government, or to such officer as the State Government may appoint in this behalf.