A 29-year-old man has been arrested on suspicion of stalking Prince Harry and Meghan Markle outside their $20 million Montecito mansion in California.

Kevin Garcia Valdovinos has reportedly been released on a $2,000 bail.

The Duke and Duchess of Sussex were not present in their nine-bedroom home when the alleged incident took place.

Security personnel saw a man creeping around the property at around 2am and police were called.

The sprawling Montecito estate, which has stunning views of California, also includes a tennis court, a children's cottage, a library, a wine cellar, a spa, a gym, a game room, a five-car garage, a tea house, and a pool.

The property contains tiered rose gardens, tall Italian cypress trees, blooming lavender, olive groves, and lawns.

In the past, the couple had reported that paparazzi photographers had flown drones as low as 20 feet over their property.

The Duke and Duchess of Sussex had indicated their fear for their children's safety on prior occasions when they noticed this happening.

This comes amid claims the pair were involved in a "near catastrophic" car chase in New York while being followed by paparazzi.

Harry's spokesman stated that the two-hour pursuit resulted in multiple near collisions with pedestrians, other drivers, and two NYPD officers.