A teenager who was fighting doctors to continue life-preserving treatment has tragically died.

The 19-year-old, who can only be identified as ST because of court-imposed reporting restrictions, died after suffering a cardiac arrest on Tuesday, the Daily Mail reports.

She was locked in a legal battle with an NHS trust after the doctors treating her said that she was "actively dying" and should be transitioned to palliative care.

The teen suffered from a rare genetic disorder called mitochondrial depletion syndrome (MDS). It was her wish to be given permission to travel to Canada to take part in medical trials for experimental treatment. 

Over 27,000 people signed a petition calling on the health secretary to intervene in the case. The petition was started by Christian Concern, which has been supporting the family. 

Speaking to the Daily Mail just days before her death, the teenager had expressed frustration at the court order and the stance of the doctors caring for her.

"I have found myself trapped in a medical and legal system governed by a toxic paternalism which has condemned me for wanting to live," she said. 

Following her death, her heartbroken family have spoken of their anger at the gagging order that still prevents her name from being revealed. 

"Even now, in the hour of our grief, we continue to be gagged by the court order from saying her name aloud," they said. 

The devout Christian family has vowed to fight for the right to reveal their daughter's name and tell her story in full. 

"We lost our beautiful and courageous daughter, known to the world as ST. To us she has a real name," they said. 

"To her family she was everything and we will cherish and never forget the 19 years we had with her.

"The past year, however, has been one of struggle, even torture, for ST and for her family at the hands of the hospital and the Court of Protection."

Andrea Williams, chief executive of the Christian Legal Centre, which has supported the family, said: "We take very seriously the privilege of serving people in their hour of need and seeking justice for them.

"The case of ST is not just about justice for her and her family but ensuring that justice in such cases is done with full transparency and proper scrutiny in this nation.

"ST was truly courageous and beautiful soul. She died advocating for the preciousness of life and importance of justice.

"As a committed Christian ST was determined to stand for life and no matter how weak and fragile she felt within the system. ST believed in the worth and dignity of every life and that such life was worth fighting for and not giving up on."