WASHINGTON — A woman who killed her abusive mother in a case that gripped the US has been released from prison after spending more than seven years behind bars.

Gypsy Rose Blanchard, 32, pleaded guilty to the second-degree murder of Dee Dee Blanchard in Missouri in 2015.

After years of abuse and invasive unnecessary surgery, she plotted with her boyfriend Nicholas Godejohn.

The case sparked intense media interest and spawned a number of documentary series and TV shows.

Gypsy Rose Blanchard walked out of Chillicothe Correctional Center in Missouri early on Thursday morning, having served seven years of a 10-year sentence.

Her boyfriend Godejohn, whom she met online, is still behind bars serving a life sentence without parole.

He stabbed Dee Dee Blanchard to death with a knife her daughter gave him and the two of them fled the scene.

A Facebook post by Gypsy Rose Blanchard in which she seemed to confess to the killing sparked concern among her mother's friends and her body was soon found.

Gypsy Rose Blanchard and her boyfriend were arrested 600 miles away in Wisconsin, where he lived. — BBC