Prince Harry and Meghan Markle sue paparazzi over 'illegal' photos of their son, Archie

The couple claim unnamed photographers took images of the 1-year-old in their private home without permission

Prince Harry and Meghan, Duchess of Sussex have moved to a new home in Santa Barbara, California. AFP

Prince Harry and Meghan Markle have filed a lawsuit in California against unnamed paparazzi photographers they allege took "illegal" photographs of their son, Archie.

"The couple recently learnt that someone is shopping photographs of their 14-month-old son, Archie, falsely claiming to have taken them on a 'recent' public outing 'in Malibu'," the complaint, filed on Thursday for invasion of privacy, said.

"But Archie has not been in public, let alone in Malibu, since the family arrived" in California, the lawsuit said, noting that the snapshots were actually taken during "activities in the backyard of the residence, unbeknownst" to the couple.

The complaint, which targets unidentified individuals, is based on a California law that prohibits taking images of anyone in their home, even from outside the property.

"No drones, helicopters or telephoto lenses can take away that right," the couple's lawyer, Michael J Kump, said in a statement.

"The Duke and Duchess of Sussex are filing this lawsuit to protect their young son's right to privacy ... and to uncover and stop those who seek to profit from these illegal actions."

Prince Harry and Meghan quit frontline royal duties earlier this year and now live in Los Angeles, the former Suits actress's home town.

The complaint accuses paparazzi of flying helicopters and drones over the couple's home and cutting holes in a security fence in order to obtain photographs.

The duke and duchess say they expect to be followed when they go out in public but state that "certain paparazzi and enablers have crossed a red line".

"The plaintiffs will not allow the tabloids to break the law, especially when it involves intimidation, harassment and the addition of a very real security threat on top of what already exists," the complaint said.

“This action arises out of the relentless and quite frankly shocking efforts of the tabloid media to profit from serial intrusions of the privacy of a 14-month-old child in his own home, and the desire and responsibility of any parent to do what is necessary to protect their children from this manufactured feeding frenzy."

Archie was most recently publicly glimpsed in May, as Meghan took part in a fundraising video in which she read to her son.

Since stepping back from royal duties, the couple have pushed back against the media's intense coverage of their private life.

“The plaintiffs have done everything in their power to stay out of the limelight, except in connection with their work, which they freely admit is newsworthy,” according to the lawsuit, which says they “simply want to continue the public impact work that is so important to them while having the private life to which any family or individual has the right.”

In April, the Duke and Duchess of Sussex told Britain's biggest tabloids, including The Sun and Daily Mail, that there would be "zero engagement" with them in future because of their false and invasive coverage.

Additional reporting by Reuters