A man and woman have been refused bail after allegedly bashing a security guard to death in front of their children last night at inner Sydney's Broadway shopping centre.

Police say Hans Schulz, 69, was trying to remove the couple after they broke into the Wendy's ice cream kiosk just after 8.00pm (AEST).

The couple allegedly responded by punching and kicking him.

Inspector Sean Beehag say the pair were with their two young children and another woman.

"With quite a violent and ferocious kick, she kicks him in the chest, forcing the security guard down on the ground before they flee the centre," he said.

Two security guards tried to revive Mr Schulz in front of shocked witnesses, but he died.

The 32-year-old man from Randwick and 27-year-old Maroubra woman were arrested at a nearby bus stop soon afterwards.

They appeared in Newtown Local Court this morning charged with manslaughter.

Neither applied for bail during the brief hearing, but it was formally refused.

Superintendent Michael O'Toole says welfare authorities have been alerted to the couple's children, aged three and five.

"They were taken to hospital and checked out and they were released from hospital into the care of their grandparents. DOCS were notified," he said.

Superintendent O'Toole says the other woman is still on the run.

"The name that we have so far is Raelene. She's aged in her mid 30s, Caucasian, female obviously, 165 centimetres tall, thin build," he said.

"At the time she was wearing a black hooded jacket, dark pants and has short dark hair.

"Raelene is just a witness to this matter. She's not wanted for arrest in relation to this matter but we believe she can provide some assistance."

Staff at the centre say Mr Schultz leaves behind a wife and children.

"He's very friendly. He's very helpful. Really he's doing his job from his heart," said Janet Areira, who works at a dry cleaners just metres from the Wendy's.

"He was a beautiful person. He wouldn't harm anyone. I'm just in shock to find out what's happened this morning," said Rhonda, a cleaner who works at a pub on the centre's ground floor.

Police are also trying to contact members of Mr Schulz's family in Germany.