Rachael Kneeland, who is in the midst of divorcing the actor, claims Furlong's "drug use has escalated along with attacking me and threatening my life," according to the Superior Court papers.
Furlong's rep, R.J. Rousso, tells PEOPLE the allegations are false.
Contentious Divorce"Mr. Furlong vehemently denies all allegations that have been made and is currently working with his legal team to have this temporary restraining order extinguished," says Rousso. "Unfortunately, the two parties are going through a very contentious divorce and custody battle. Eddie's main concern is his son, Ethan, and moving forward with his life."
The rep adds: "Eddie has been sober for more than five years and is preparing to begin production on a new film."
In her court papers, Kneeland alleges that on Sept. 23 Furlong "grabbed me, bruised me, pushed me ... left messages saying he would hire people to come and beat me with chains and bats. He is smoking cocaine and doing other various drugs. He is very unpredictable."
Upcoming HearingBy the following day, Furlong allegedly sent more than 20 threatening messages to her, and the actor was in "lockdown after threatening suicide and I called 911," Kneeland adds.
A judge on Sept. 25 temporarily ordered Furlong to stay 100 yards away from Kneeland (who also uses the last name Bella), and has stripped him of visitation rights for their 3-year-old son. A court hearing is set for Oct. 20.
A friend of Furlong's confirms the actor was detained and has since been released. The source denies the actor is using drugs again but acknowledges the split from Kneeland has taken its toll.
"He has gotten really upset – anybody would," the friend says of Furlong, who is slated to start production on The Green Hornet this weekend. "We're trying to get him back to a place where he's calming down and talking to everybody."