I suspect that either this was some confidential informant who just reported false claims about Afroman and the police used it to get a warrant. Or the whole department is just corrupt and make up stuff to get a warrant in order to raid his house hoping to forfeiture his money.
They also claimed that they're received hundreds of calls one day, with violent threats from some anonymous individual, and when they tried to track the number, it didn't work, "the numbers didn't actually exists" or something like that, and there is no way of proving the calls actually happened, except for the call log at their police station.