The young boy discovered concealed beneath floorboards in his Arkansas home had passed away for 15 weeks — authorities say he lost his life after his mother’s boyfriend forced his head underwater as a form of “punishment,” according to court records.

Blu Rolland’s remains were found Friday — his sixth birthday — wrapped in multiple layers of plastic and hidden under newly secured boards inside the home in Moro, according to an affidavit obtained by NBC News.

His father’s family had raised concerns after Blu’s sister was found with serious injuries — and the boy had repeatedly been kept from scheduled custody visits.

Blu’s 28-year-old mother, Ashley Rolland — who appeared with visible facial injuries in her booking photo — blamed her boyfriend, Nathan Bridges, 33, after both were arrested the day following the discovery, the outlet reported.

She told investigators that her partner was responsible for Blu’s death on Sept. 9, alleging he forced the child’s head underwater as punishment for biting his finger, the affidavit said.

The mother claimed she was in another room at the time and entered the bathroom after Bridges left, where she saw her son unresponsive and struggling.

She told police that her boyfriend then cut through the wooden floor, created a space beneath the house, and concealed Blu’s body there.

However, a witness named Rebecca Fiting told investigators that Ashley Rolland had said Blu came out of the bathroom with swelling and distress before collapsing.

The mother reportedly said she did not know what to do and hid Blu beneath the floorboards, according to Fiting, whose relationship to the suspect was not detailed.

The children’s father, Dustin Rolland, 30, filed a complaint about being denied court-ordered visitation on Sept. 14 — unaware that his son had already passed away days earlier, according to the timeline provided.

It was his mother, Karen Rolland, who ultimately contacted authorities after Blu was again not brought for visitation — while his sister appeared with severe untreated injuries.

The grandmother told NBC News that the girl’s clothes were soaked, she could barely walk, and her first request was for water and food.

“I told her that she was safe, and just the look on her face was sheer terror,” she said.

Ashley Rolland told police that Bridges was also responsible for the injuries to her daughter, alleging he held her under extremely hot water as punishment for behavioral issues, according to the affidavit.

An online fundraiser that had raised more than $25,000 by Friday described extensive injuries across the girl’s body.

“This child’s hair had been cut off, she is undernourished, had fractured ribs, and numerous injuries in various stages of healing,” it said.

Ashley Rolland and Bridges face charges including capital homicide, improper handling of human remains, tampering with evidence, child endangerment, and assault. Rolland also faces additional felony charges related to allowing harm to a minor.

Both are being held without bond and are scheduled to appear in court Jan. 17.

The children’s father told NBC that he had “been trying to fight for my kids.”

“I wish I could’ve been there sooner, but I was being kept from my children,” he said of his ex-wife, whom he married in December 2015 before divorcing last year.

“I don’t want anybody thinking that this was my fault. I love my kids very much,” he said.