![FILE PHOTO - Otto Frederick Warmbier (C), a University of Virginia student who was detained in North Korea since early January, is taken to North Korea's top court in Pyongyang, North Korea, in this photo released by Kyodo March 16, 2016. Mandatory credit REUTERS/Kyodo ATTENTION EDITORS - THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS. MANDATORY CREDIT. JAPAN OUT. NO COMMERCIAL OR EDITORIAL SALES IN JAPAN - RTS16VUW](https://a57.foxnews.com/static.foxnews.com/foxnews.com/content/uploads/2018/09/1200/675/otto-warmbier-nk.jpg?ve=1&tl=1)
Otto Warmbier died after he was returned to the U.S. by North Korea with a severe brain injury. (Reuters)
The parents of Otto Warmbier are suing North Korea for over $1 billion, saying their son died as a result of being tortured while in captivity.
The suit, which was originally filed in April, alleges that North Korea "tortured him (Warmbier), kept him in detention for a year and a half without allowing him to communicate with his family, and returned him to them in a non-responsive state and brain dead."
The college student from Ohio was on a tour in the communist country when he allegedly stole a propaganda sign from a hotel. He was arrested in January 2016 and held captive by North Korea for more than 17 months.
He died from severe brain damage after he was repatriated to the U.S. in June.
The court documents filed in October reveal that Warmbier’s parents are seeking $1.05 billion in punitive damages and about $46 million for the family’s suffering.
North Korea has repeatedly denied the accusations that he was tortured.
The Associated Press contributed to this report.