Britney Spears' legal representative has launched a fierce counter-attack against claims suggesting the pop star's involvement with drugs.

Matthew Rosengart, Spears' influential attorney, vehemently disputed a "groundless and defamatory" Daily Mail article that associated the "Toxic" performer with the use of methamphetamine. According to Page Six, Rosengart addressed a legal letter to the publication on Sunday.

Rosengart purportedly insisted on an in-house probe into allegations of the manipulation of Spears' minor children, Sean Preston, 17, and Jayden, 16, whom the singer co-parents with her former husband, Kevin Federline.

"The Daily Mail, in collaboration with Daphne Barak, published a narrative yesterday saturated with numerous erroneous and libelous assertions about my client Britney Spears, attributed to Kevin Federline and his children. This specifically pertains to references about 'crystal meth,'" Rosengart's letter commenced.

The lawyer further stated that Federline, who was married to Spears from 2004 to 2007, "has admitted that Ms. Barak's narrative is inaccurate." Rosengart also pointed out Barak's alleged repeated attempts to make contact with Spears.

"I have separately discovered that Ms. Barak tried to establish contact with Britney on multiple occasions under false pretexts, involving her minor children. This behavior is exploitative, intrusive, and outrageous," Rosengart's letter proceeded. "Moreover, Britney's representatives were never consulted prior to the story's publication, demonstrating intentional malice and a reckless disregard for the truth."

He concluded, "While Britney is indeed a public figure, this behavior is unacceptable and crosses the line. Even by current 'journalism' standards, this falls short and exemplifies the unjust scrutiny she has had to endure."

In her report, Barak claimed Federline, a professional dancer, had confided suspicions about Spears' alleged drug use, an assertion Federline refutes.

Barak attributed a quote to Federline in her report, stating, "I fear [Britney's] on meth – I've been praying someone would make it public and that she wakes up ... It's terrifying. She is the mother of my boys."

Responding to TMZ, Federline said, "We welcomed Daphne & Bill into our home due to our trust in them, a trust that was later betrayed, leading us to cut ties in March for reasons we prefer not to delve into."

He added, "It's deeply distressing that she persists in bothering our family despite repeated pleas to be left alone. Our family did engage in a few discussions with Ms. Barak and Mr. [Erbil] Gunasti, which were conducted with respect, compassion, and concern for Britney and the Spears family. Her fabrications and exploitation of minors are yet another deplorable example of the decline of certain journalistic standards today."

Spears also shared on Instagram that she felt targeted by the report, expressing hope that neither Federline nor their son Preston had made the alleged statements.