@silvester. my dear friend, as she has filed 125, you need to be worried about that first, assuming that you are only fighting your 125 case, then why are you worried about proving your potency, when no other case has been filed, besides the 125 case (going by your reply, she has only filed 125 case)
maintainence case is a totally different case altogether, dont mix it up with your potency test!! in maintainence case, you have to prove that she is working, if you cannot prove, then you have to start paying maintainence in the interim, the arguments are on the later stage, so get ready to pay if she is not working or if you are not able to prove that she is presently working.
the bald allegations of impotency, blah blah are all standard formats of lawyers, in order to draw the judges attention and sympathy, if she files case on you for divorce on grounds of impotency, along with the 125, there the court will ask you to undergo a medical examination from a government hospital as directed by the court,. the police is not involved in the medical examination, as mentioned above (it is not a rape case for heavens sake!!) so why will the police be involved. you will submit yourself on the directions of the court to a particular govt hospital for potency and other tests,m and the results will be sealed and delivered in court. even then, potency or impotent cannot be judged 100% as a man is prone to be impotent with a particular women and not with other women. so dont worry about the potency test, worry about the maintainence first