Nathan Matthews suffocated his stepsister in her bedroom in Bristol in February 2015 following a sexually motivated kidnap plot.

He and his girlfriend Shauna Hoare targeted Becky because of their shared dislike of her and their sexual interest in petite teenage girls.

Matthews, then 28, was jailed for life with a minimum term of 33 years after he was found guilty of murder, while Hoare, then 21, was handed a 17-year sentence after she was convicted of manslaughter.

Both were found guilty of kidnap, perverting the course of justice, preventing a lawful burial and possessing two stun gun torches.

Because she only received a determinate sentence, Hoare, now 29, was automatically released from prison on licence halfway through her sentence without the involvement of the Parole Board.

Becky's mother Tanya Watts said she "knew this day was coming" and was told in a phone call on Friday morning.

"She's not even 30, she's got her whole life ahead of her and she's got a future, whereas when we go to talk to our daughter, we're talking to the ground," she told Bristol Live.

"The main feeling is anger, I'm so angry, but what can I do?"

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"It's been hanging over me for a while, and I've been counting down the days, but now she's out there somewhere, what can I do? How do I feel?

"I don't want her to feel like she's free to walk down the street without a care in the world, after what she did. I think she's cold and evil."

After Becky was killed, Matthews and Hoare bundled her body into their car before driving it to their home, where it would later be dismembered in their bathroom.

Her remains were then hidden in a nearby shed, where they were eventually discovered weeks later.

One of the conditions of Hoare's release reportedly prevents her from returning to Bristol, although the Ministry of Justice (MoJ) would not comment on details of her release.

An MoJ spokesperson said: "We know this will be an incredibly difficult time for Becky Watts' loved ones and our heartfelt thoughts remain with them.

"Offenders like Shauna Hoare face some of the strictest licence conditions and can be put back behind bars if they break the rules at any point.

"We've also since changed the law so the most heinous offenders face longer than ever in prison."