Two managers have been sacked and two others have been transferred following the escape of six people from Sydney's Villawood Immigration Detention Centre.
Nine people initially escaped from the complex in Sydney's southwest in the early hours of Tuesday, May 25.
Three were detained by police as they escaped, but six others, all Chinese nationals, remain at large.
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Serco, the UK-based security company that manages the centre, undertook a "comprehensive investigation" following the escape, Serco spokeswoman Emma Needham said in a statement.
"Serco has dismissed two employees today and redeployed two others following an internal investigation into last week's escapes from Villawood," she said.
Fine, sanctions possible
"In order to take the management of the centre forward and deliver the transformation required, changes to a number of positions were necessary."
The company faces fines and sanctions imposed by the federal government following the escape.
Immigration Minister Chris Evans has ordered an investigation into the breakout, the latest in a series of escapes from Villawood.
Serco also manages security at the Maribyrnong Detention Centre in Melbourne's western suburbs.
It came under fire after a Chinese national slipped away from two Serco security staff while on a visit to the Melbourne Aquarium in March.
