In Star Trek V, why was the Klingon Bird-Of-Prey hanging close to Earth?

Question

The sequence at the beginning of Star Trek V: The Final Frontier shows the Pioneer 10 probe being destroyed by a Klingon Bird-Of-Prey.

Given the speed of the probe, even in 2287, the year the movie takes place in-universe, it wouldn't be very far from Earth's solar system. Which means that the cloaked Bird-Of-Prey was, for some reason, discreetly flying close to the capital of the Federation while the Organian Peace Treaty was in force.

Was it ever explained why that Bird-Of-Prey was so close to Earth?

Answer 1

According to the film's official novelisation, the probe had (somehow) made its way into Klingon space. No explanation is given as to quite how it managed this feat, although we do know of other pre-warp objects from Earth that have traveled suspiciously large distances and non-warp-capable ships that still managed to achieve warp velocities.

THE ANCIENT PROBE hurtled aimlessly through the blackness of uninhabited space. Its designers were long dead, its purpose forgotten; it was now no more than a piece of flotsam, like the millions of bits of celestial debris that had collided with it, scarring its once-smooth surface. Still visible on one side of the probe, etched into the metal, were images: two naked adult humans, a male and a female, hands raised in a gesture of greeting. Beside them were various mathematical and scientific symbols. The probe had obviously been launched by humans who hoped to contact intelligent extraterrestrial life forms.

Ironic, thought First Officer Vixis, that it should encounter them here, centuries later, in the Klingon empire.