Anne Heche is still in a coma with significant burns and lung damage following the incident last Friday in which she drove her car into a house in Los Angeles, according to her representatives.
Heche, 53, was taken to hospital in a critical condition following the crash in the Mar Vista area of the city.
In a statement shared with US media outlet People, her representatives said: "She has a significant pulmonary injury requiring mechanical ventilation and burns that require surgical intervention.
"She is in a coma and has not regained consciousness since shortly after the accident."
Reports at the weekend that suggested she had been driving at speed down an LA street before crashing into the house and suffering severe burns.
According to the Los Angeles Fire Department, the crash sparked a "heavy fire", which was later put out after an hour. Crews took the driver to hospital with "critical injuries".
Such was the force of the impact that the blue Mini Cooper that Heche had been driving penetrated 30 feet into the two-storey home.
According to the Los Angeles Fire Department the home's occupant was uninjured but the property was left uninhabitable.
The next door neighbour of the house which was hit, who was first on the scene at the incident, told Fox News: "I saw a car speeding by in front of my house and a few moments later I heard a crash.
"[The car] went all the way through the house to the back of the house.
"The windows were broken, so I opened the back door of the car."
"She finally answered and said she was not okay, so that was tough."
"I know they didn't get her out of the car until the fire was pretty much put out."
The neighbour added he helped the person leave the home after the collision.
Heche is known for her roles in films including Psycho, Donnie Brasco and Cedar Rapids - and she previously dated Ellen DeGeneres between 1997 and 2000.