LOS ANGELES • Pop star Britney Spears has sought to reassure fans concerned for her mental health, saying she is "the happiest I've ever been".

Spears, 38, whose business and personal affairs are controlled by her father Jamie Spears, posted an Instagram video in which she addressed persistent reports that she was not doing well.

"I know that there have been a lot of comments and a lot of people saying a lot of different things about me, but I just want to let you guys know that I am fine," the singer said in the video on Monday.

A small but vocal group of fans has launched a #FreeBritney campaign that seeks to end a court-ordered conservatorship that was put in place about 12 years ago.

Mr Spears was appointed conservator in 2008 after the pop star was hospitalised for psychiatric treatment. The singer's care manager Jodi Montgomery took over in a temporary capacity late last year when Mr Spears suffered a bout of ill health.

In August, Spears asked for Ms Montgomery to permanently replace her father as her conservator, but a closed-door court hearing extended the current arrangements until February next year.

Supporters of the #FreeBritney campaign believe Spears is being kept prisoner in her Los Angeles area home and that she is sending cryptic signals begging to be freed through her social media accounts, which usually consist of selfies or dancing.

Other fans have expressed alarm about repeated Instagram postings of the same photos, apparently taken years ago.

Spears - known for hits including Toxic, (You Drive Me) Crazy and ...Baby One More Time - revived her pop career after her breakdown, but she pulled out of a Las Vegas concert residency last year and briefly entered a mental health facility.

She has not performed publicly since October 2018.

REUTERS