The singer and her ex have been fighting over post-nuptial agreements, spousal supports and custody of their twin daughters, Harper and Finley, both 10.
In March, a psychologist was appointed by the court to evaluate Lisa's daughters amid the bitter divorce war. Lisa Marie has been fighting for full custody of the girls.
The tax lien is likely to add more pressure to the mother of four, who also shares daughter Riley, 30, and son Benjamin, 26, with Danny Keough. Earlier this year, sources told RadarOnline.com that Lisa's friends were worried sick over her drug use.
"It is a miracle Lisa Marie is still alive," one pal told RadarOnline.com.
Lisa Marie has battled addictions to cocaine, prescription pills and booze in the past. Shocking court documents obtained by RadarOnline.com earlier this year claimed the mother of four was "paranoid and hallucinatory" after abusing cocaine.
The court filings also revealed that Lisa Marie's ex claimed to the Los Angeles Department Children and Family Services that the troubled singer popped "up to 80 opiate pills a day."
- Lisa Marie Presley’s 14-Year-Old Twins ‘Traumatized’ By Mom’s Death At Their Home, Refusing To Go Inside $4 Million Mansion
- Lisa Marie Presley Entered Rehab Four Years Before Tragic Death In Effort To Prove She Was Serious About Sobriety: Sources
- Priscilla Says Lisa Marie & Kids Are ‘Great’ Amid Nasty Divorce & Custody Battle
Lockwood also claimed that his ex-wife stayed awake for 11 days straight in 2015.
After authorities began to investigate Lisa Marie's drug habits, she checked herself into rehab. The estranged couple's 10-year-old daughters lived with their famous grandmother Priscilla Presley at the time. The investigation was ultimately dismissed in 2017 due to lack of evidence.
The scary encounter led Lisa Marie to attempt to clean her life up.
"She finally realized that she was killing herself, and decided that she didn't want to end up like her dad," a source told RadarOnline.com.