Kautilya's Arthashastra 4.12.35

4.12.35

keśākeśikaṃ saṃgrahaṇam, upaliṅganād vā śarīropabhogānām, tajjātebhyaḥ(tajjñātebhyaḥ? cfṇ12.60)), strīvacanād vā //

(Adultery may be proved by circumstances such as) hand to hand fight, abduction, any marks made on the body of the culprits, opinion of experts on consideration of the circumstances, or the statements of women involved in it.