Why does government try to learn about testicles and erections of some athletes?

Certain sportspersons who are accused of steroid use become targets of the government. Federal prosecutors do almost everything in order to determine whether certain athletes have administered any performance-enhancing drugs. They don’t spare taxpayers’ funds for this purpose. Much money is spent to disclose even private life of sportspersons. According to the government, some details of their private behavior can disclose the truth about usage of banned medications. So, girlfriends of several sportspersons are interviewed by feds.
For example, it has been revealed that former girlfriends of Lance Armstrong and Roger Clemens and a former mistress of Barry Bonds have been asked about several details linked with private life of these sportspersons. Which questions were asked?
Kimberly Bell, a former mistress of Barry Bonds, was asked about size of testicles of this baseball player. She affirmed that the baseball player’s testicles were shrunken. So, her answer served as an argument that Barry Bonds used steroids and/or other prohibited products.
It is known that shrinkage of testicles is included in undesirable results of some steroids. So, the government decided to find out whether Barry Bonds had had this trouble. But it is a poor argument in order to prove that anyone has taken certain banned medicines. Steroid users may prevent this adverse effect, if they apply some medicines for this purpose.
Mindy McCready, a former mistress of Roger Clemens, was asked whether this former baseball player had suffered from erectile dysfunctions. The singer claimed that sometimes Roger Clemens had suffered from this problem.
As for erectile dysfunctions, they may occur during usage of steroids. But if you study information about unwanted effects of steroids more attentively, you can comprehend that this problem is more likely to appear after discontinuation of administration. It happens because natural production of testosterone is normally suppressed by usage of exogenous testosterone. But since there are such medications which are capable to restore natural testosterone production, erectile dysfunctions can be avoided.
Sheryl Crow, a former girlfriend of Lance Armstrong, was also interviewed by federal prosecutors. But questions have not been made public. According to several suppositions, she might have been asked also about sexual abilities of the cyclist.
In fact, federal prosecutors have a wrong opinion in this case. Although shrinkage of testicles and erectile dysfunctions may occur because of steroids, these arguments are not proper.