A judge has granted three subpoena's on LA photo agencies who may have obtained illegally obtained pictures of Meghan Markle and Prince Harry's son Archie that were shot by a drone, according to reports.
The Sussexes' lawyer says Archie "has not been in public since the family arrived" in Los Angeles.
It is a step forward for the couple's legal bid to try and ban the publication of photos of their 14-month-year-old, they say were shot by drone on private land.
Harry, 35, and Meghan, 38, filed the suit last week in a bid to protect their son from what they call a paparazzi "feeding frenzy".
They have accused photographers of "intimidation, harassment and the addition of a very real security threat on top of what already exists."
As well as the drones, paps are accused of flying helicopters overheard and cutting holes in the couple's security fences to try and get a glimpse.
The invasion of privacy lawsuit is against unnamed defendants and references California laws against filming or photographing people on private property.
On Friday couple's lawyer Michael Kump, said in a written submission to to LA Superior Court Judge Craig Karlan at a hearing in Santa Monica they are trying to unmask those individuals or agencies who may seek to profit from the snaps.
The MailOnline reports Judge Karlan granted Kump’s application on Friday to serve subpoenas on three LA photo agencies which may be in receipt of the drone images, which the attorney also claims were deliberately mislabelled as a "public outing" in a veiled attempt to get round privacy concerns.
The court orders will reportedly be immediately served on three major US photo agencies in an effort to find the photographers responsible.
Mr Kump says his clients are treating the matter as a race against time.
In his written submission Mr Kump reportedly noted: "Archie has not been in public since the family arrived here.
"This is not an innocent mistake, but an intentional attempt to evade liability.
"The Duke and Duchess of Sussex are filing this lawsuit to protect their young son's right to privacy in their home without intrusion by photographers, and to uncover and stop those who seek to profit from illegal action.
"This is a race against the clock because there is a significant risk these illegally-taken photos could be published in the United States or United Kingdom any day."
The snaps were allegedly taken by drone flown over Hollywood producer Tyler Perry’s $18 million Beverly Hills mansion where Prince Harry and Meghan have been living since March.
The 25,000 square foot mega mansion features 8 bedrooms and 12 bathrooms and is tucked away in the mountains above Beverly Hills and lies at the back of a 24/7 guard-gated community known as Beverly Ridge Estates.