United Kingdom, Jan. 26 -- Billy Ray Cyrus' son has claimed the singer threatened legal action after he expressed concern about his famous father.

The 'Achy Breaky Heart' hitmaker' caused concern with his bizarre performance at Donald Trump's Liberty Inaugural Ball on Monday (20.01.25), prompting his eldest son Trace Cyrus, 35, to urge him to seek help because he and his sisters Brandi, 37, Miley, 32, and Noah, 25, are "genuinely worried" about him, but he has now branded his dad a "disgrace" for his alleged response to his public message.

The former Metro Station frontman wrote on Instagram: "Dad my message was beyond loving.

"I could have been extremely honest about a lot more but I don't want to put your business out there like that...