Britney Spears' 8-year-old niece is critically injured after a terrible quad bike crash.

The eight-year-old niece of US singer Britney Spears is in a critical but reportedly stable condition after an off-roading accident on the singer’s Louisiana property.

Maddie Aldridge, the only daughter of singer Jamie Lynn Spears, was airlifted to hospital after the all terrain vehicle (ATV) she was riding in reportedly flipped over into a lake on Sunday afternoon.

According to a statement by Tangipahoa Parish Sheriff Daniel Edwards, the girl was submerged underwater for minutes before being rescued.

Maddie was steering the vehicle at the time and, in trying to avoid a drainage pipe, over-corrected and entered the pond.

Another wonderful fair performance????Proud of our girl❤️

A photo posted by Jamie Lynn Spears (@jamielynnspears) on Oct 29, 2016 at 2:27pm PDT

Jamie Lynn Spears, 25, as well as Maddie’s stepfather, Jamie Watson, were both present when the accident occurred.

“The ATV and child were instantly submerged in the water right before their eyes,” the statement from police reads. “Within seconds the child’s mother, stepfather and other family members reached the pond, dove in and attempted to rescue the child to no avail. The child was trapped and secured by the seat-belt and the ATV’s safety netting.”

Ambulance services arrived within minutes and helped free the child from the water.  

Britney has shared an image of her niece to social media, with the caption:‪ “Need all the wishes and prayers for my niece.”‬

‪Need all the wishes and prayers for my niece ????‬

A photo posted by Britney Spears (@britneyspears) on Feb 6, 2017 at 2:14pm PST

Miley Cyrus in the making ????

A photo posted by Britney Spears (@britneyspears) on Sep 1, 2016 at 6:58pm PDT

A rep for the family told Fox News, “Right now the Spears family asks that everyone respect their privacy during this time and appreciates all the prayers and support for their family.”

As well as this, Spears’ father, Maddie’s grandfather, told ET, “All I can say is pray for our baby Maddie.”

Maddie is being cared for in New Orleans hospital, where doctors say she is in a critical but stable condition.