American singer-songwriter Lisa Marie Presley's ex Michael Lockwood has expressed concerns over her sobriety following the death of her son Benjamin Keough.nAccording to People Magazine, Lockwood filed court documents on Thursday, ahead of the former couple's divorce and custody trial, set for August 3. The duo--Lockwood and Presley split in 2016 after 10 years of marriage. They share 11-year-old twin daughters, Harper and Finley.nThe Blast obtained the fling which says that Lockwood has asked the court to strip Presley of primary custody, claiming "new and significant concern" over her potentially relapse.n"Lisa Marie Presley's son shot and killed himself in her home (Although she was not there at the time.) Jennifer Lopez Calls Fiance Alex Rodriguez by His Jersey Number as She Wishes Him Birthday With an Adorable Video

With all due sympathy and respect, this creates a new and unaddressed twofold problem: the safety of the children and the greater likelihood of [Presley] to relapse into drug and alcohol dependency," the filing stated.nA representative for Presley did not immediately respond to People magazine's request for comment.nPresley's 27-year-old son Benjamin, whom she shared with ex-husband Danny Keough, died on July 12. It’s OFFICIAL: The Kissing Booth 3 Is Filmed and Ready For Streaming in 2021, Netflix Drops Exciting Sneak Peek (Watch Video)

Following Benjamin's death, a rep for Presley told the outlet that she is "completely heartbroken, inconsolable and beyond devastated," adding, "she adored that boy. He was the love of her life."