“American Idol” winner Laine Hardy is most likely singing the blues Friday after being locked up for allegedly planting a listening device in a female student’s residence at Louisiana State University.

The country crooner, 21, announced Thursday that he was under criminal investigation by the LSU Police Department — but did not disclose any further information.

On Friday morning, LSU spokesman Ernie Ballard confirmed Hardy’s arrest in a statement to The Post:

“Laine Reed Hardy (Non-LSU student) was arrested by LSU Police today and booked into East Baton Rouge Parish Prison for violation of 15:1303 — Interception and Disclosure of Wire, Electronic, or Oral Communication. His arrest warrant has been filed with clerk of court.”

The singer —  who was set to perform with the fresh crop of “American Idol” contestants on Monday — is accused of hiding a digital recorder at his ex-girlfriend’s campus accommodation at Azalea Hall in order “to monitor her conversations” when they broke up, after dating from November 2021 through February 2022.

According to prison booking documents, “the victim advised that last night, while watching a movie with her roommate, [they] located a device, appearing to be a phone charger under the victim’s futon.” After some googling, “she learned it to be a VR-500 Voice Activated Recorder.”

Hardy did not respond to The Post’s requests for comment before surrendering to authorities this morning — but he did speak to his 737,000 followers on Facebook last night, declaring the LSUPD issued “a warrant due to allegations made against me.”

He did not specify what he was accused of but noted he was “fully cooperative” with cops as more than 16,000 of his fans posted emoji reactions and messages of support.

“I understand that my career has thrust me into the public spotlight, and I embrace that wholeheartedly as my entire world belongs to my music and my fans,” wrote Hardy, who won Season 17 of ABC’s “Idol” in 2019 and is known for his hits “Memorize You” and “Flame.”

His post continued, “However, due to the sensitive nature of this allegation, I humbly ask for privacy at this time. I have the utmost respect for the law and will assist in their investigation as needed moving forward.”

Hardy’s booking document goes on to state that in mid-February, “the victim … found a fake Instagram on the Defendant’s phone that he used to cover up that he was illegally recording her when he was not around.”

The docs also point out that Hardy “had information about the victim and her actions during Christmas break that was not known to the defendant.” When the female student “confronted” Hardy he “admitted that he left a ‘bug’ in her room later discarded it in his pond,” according to the report.

After the victim discovered the device still in her room — she turned it over to LSUPD, at which time the authorities found audio of his “distinguishable voice” and heard his name being repeated by other parties. On the second to last recording, dated Feb. 2, the “victim is heard telling someone about how she figured out the Defendant was recording her” — but she “doesn’t know if the bug is still in her room.”

When contacted for comment about the charges, Hardy’s reps told The Post they could not comment on the “pending investigation.”

However, his attorney C. Frank Holthaus confirmed that “Mr. Hardy did receive a warrant for his arrest [Thursday] and has been and will continue to be completely cooperative with the Baton Rouge Police Department on this matter. Due to the public nature of Mr. Hardy’s profession, we ask for privacy at this time.”

Hardy — a native of Livingston, Louisiana — also made headlines in June 2020 when he and his rumored then-girlfriend Sydney Taylor, an LSU student and Miss Teen Louisiana, revealed that they had tested positive for COVID-19.

“This isn’t what I expected on the first day of summer,” he posted on Facebook at the time. “My doctor confirmed I have Coronavirus, but my symptoms are mild and I’m home recovering in quarantine. Y’all stay safe & healthy!”