LOS ANGELES – Nick Carter, a member of the pop group Backstreet Boys, filed a restraining order against his brother Aaron, alleging that he threatened to kill his wife and unborn child.

“After careful consideration, my sister Angel and I regret that we were required to seek a restraining order against our brother Aaron today,” the 39-year-old singer wrote on Twitter on Tuesday.

“In light of Aaron’s increasingly alarming behavior and his recent confession that he harbors thoughts and intentions of killing my pregnant wife and unborn child, we were left with no choice but to take every measure possible to protect ourselves and our family,” he added.

“We love our brother and truly hope he gets the proper treatment he needs before any harm comes to himself or anyone else,” concluded the singer, who is expecting his second child with wife Lauren Kitt.

Nick ended his tweet with hashtags for mental health and gun control.

Meanwhile, Aaron, who is also a singer, responded on Twitter saying he “never threatened anyone.”

“I’m appalled by this and don’t ever wish to speak to them again,” he added in one of multiple tweets he posted since the news broke out.

In another tweet, Aaron said he hadn’t seen his brother for four years and in yet another he declared that they were “done for life.”

“I am astounded at the accusations being made against me and I do not wish harm to anyone, especially my family,” he reiterated in successive messages.

News of the restraining order comes after Aaron spoke about his history of addiction and drug use on a TV show on Friday, in which he revealed the long list of medications he takes for his mental health.