The whole thing was a setup. The "girl" was not a girl at all. "She" was an alien being from the planet Robitusin, which orbits a star about eighty light-years beyond Sirius.

Well, "she" wasn't actually the being itself. The being is still alive and well. You see, Robitusians have the ability to use raw materials readily available in the air and soil of other planets to cloak themselves in guises closely resembling life-forms of whatever planets they may be on. When they're through with their disguises they usually return the raw materials to whatever sources they borrowed them from. Something must have happened which made the Robitusian leave the prostitute's "body" in it's complete state.

As for the chimp found with the dead prostitute, it obviously wasn't Chongo. Chongo may fantasize about making it with human women, but when it gets down to the nitty-gritty he always chickens out. Even being propositioned by a human prostitute would have sent Chongo running away yelling "Ook-ook! Jabba-jabba!" as fast as his four legs could carry him.

Exactly why this charade was carried out is still being worked out. It's possible that the Robitusian agent may have been attempting to contact The Leader of the Free World who is rumored to bear a remarkable resemblance to Chongo and his relatives. Why the Robitusian chose to disguise itself as a streetwalker is another unknown, though it's possible that it may simply have not realized that it was the previous Leader of the Free World for whom a floozy would be a surefire attractant.