The Duke and Duchess of Sussex have fired another salvo against the British media by issuing a legal letter accusing the BBC of “false and defamatory” reporting over a story regarding their newborn daughter Lilibet’s name.

The latest spat centers around whether or not the couple asked Queen Elizabeth II for permission to use her personal nickname, “Lilibet,” for their daughter. “Lilibet” was the name used in private by the Queen’s father and her husband, Prince Philip. During Philip’s funeral in April, reports suggested that a hand-written card from the Queen, which accompanied a funeral wreath atop Philip’s casket, had been signed “Lilibet”.

Some media reports initially claimed that Harry and Meghan, who are currently on parental leave, consulted the Queen before using the name for their daughter. However, the BBC’s long-time royal correspondent Jonny Dymond reported this morning that he had been informed by a “palace source” that the Queen had not been asked.

Dymond included in his report a rebuttal from the Sussexes’ spokesperson, who told him: “The duke spoke with his family in advance of the announcement — in fact his grandmother was the first family member he called. During that conversation, he shared their hope of naming their daughter Lilibet in her honor. Had she not been supportive, they would not have used the name.”

After other media outlets picked up on the BBC’s report, the Sussexes instructed their London-based law firm Schillings to send out a threatening legal letter calling the BBC’s report “false and defamatory.”

Variety has contacted the Sussexes’ reps for comment.

The legal warning shot represents another blow for the BBC in its relations with the royals, after being roiled by allegations that one of its former star correspondents, Martin Bashir, used forged documents in order to persuade Harry’s mother, Diana, Princess of Wales, into sitting down for her infamous Panorama interview. An external investigation, which concluded last month, found that the BBC “fell short of the high standards of integrity and transparency which are its hallmark” in its conduct regarding the interview.

“To those who have taken some form of accountability, thank you for owning it,” Harry said in a statement last month. “That is the first step towards justice and truth. Yet what deeply concerns me is that practices like these — and even worse — are still widespread today. Then, and now, it’s bigger than one outlet, one network, or one publication.”