A Queensland police officer involved in a car chase that killed two pedestrians has told an inquest he thought he was going 30km/h slower than he was.

A Queensland policeman involved in a car chase that resulted in the deaths of two pedestrians has told an inquest he didn’t check his speed or sound the siren.

Acting Sergeant Philip Brock thought he was driving at 150km/h as he pursued West Australian drink-driver Brett Glenbar on the night of December 4, 2009.

But an internal police analysis of CCTV footage from a service station at Park Ridge, south of Brisbane, showed he was travelling at more than 180km/h in an 80km/h zone.

“I did not look at the speedo but I estimated 150km/h,” Sgt Brock told the inquest in Brisbane.

Asked by counsel assisting the coroner Peter Johns if that was “unacceptably fast”, Sgt Brock replied: “I believe it’s fast.”

Sgt Brock also admitted the police siren had not been turned on during the chase.

“I don’t recall the siren being activated,” he said.

Senior Constable Lisa Harmer, who was in the passenger seat during the chase along Chambers Flat Road, told the inquest she should have told her colleague to slow down.

“I was the senior officer in the car,” she said.

“If I was concerned about the speed, I should’ve said something, told him to slow down as the senior officer.”

Const Harmer, who was disciplined along with Sgt Brock, agreed with Mr Johns’ suggestion that she should have been concerned about the speed.

“You said you weren’t concerned about the speed?” Mr Johns said.

“No,” Const Harmer replied.

Under questioning from the counsel for the Queensland Police Union, Calvin Gnech, Const Harmer answered no when asked if the police service had provided counselling or welfare support after the fatalities.

Glenbar, the driver of the pursued rental car that slammed into and killed the pedestrians, is serving 10 years in jail for the manslaughter of Brisbane couple Ronald Ellison, 46, and Jacqueline Sylvester, 40.

Changes to Queensland laws in 2011 restrict police pursuits to circumstances of life being under threat or homicides, following an inquest into police pursuit-related deaths.

The inquest before state coroner Terry Ryan has been adjourned.