Staff at Broadway Shopping Centre have described a security guard killed in an alleged bashing overnight as a "very nice" man, as a couple faced court charged with manslaughter.

Witnesses said Hans Schulz, 69, was kicked and punched several times when he confronted a couple who had allegedly broken into Wendy's ice-cream shop on the ground floor about 8.10pm, police said in a statement.

Svetlana Avrashkova, 27, from Maroubra, and Adrian Gallaher, 32, from Randwick, were later arrested at a bus stop at Railway Square.

Police at the scene ... two people have been arrested following the death of a security guard.

Police at the scene ... two people have been charged with manslaughter following the death of security guard Hans Schulz. Photo: Esther Han

Superintendent Michael O'Toole said Mr Schulz was the victim of a "vicious" attack after he approached the couple, who had just bought groceries from Coles.

Mr Schulz was taken to Royal Prince Alfred Hospital, where he died a short time later.

A worker from a nearby sushi shop said she saw Mr Schulz get kicked in the head.

Security

Security guard death ... NSW police dust for fingerprints. Photo: Esther Han

"Then he fell to the ground and his face changed colour. It went blue," she said.

She said she knew the man because she would see him at work on Sundays, but she did not know his name.

"He was very nice. I feel very sorry for him."

Victim ... Hans Schulz.

"Very nice" man ... Hans Schulz.

Police said they were also trying to track down a third person, identified as Raelene from Surry Hills, but she was wanted only as a witness, not for arrest.

It was unclear why the couple had allegedly broken into Wendy's, police said.

"It's hard to say at this stage as to what their intentions were but they had certainly gained access to one of the shops after trading hours," Detective Inspector Paul Pisanos of Leichhardt Local Area Command said yesterday.

Police sealed off the area last night, photographing and taking fingerprints.

The couple appeared in Newtown Local Court this morning. They did not apply for bail and it was formally refused.

Their legal representation, Fiona McCarron, said both had exercised their right to come back before the court in seven days so the matter was adjourned. Both had requested medical attention.

A report will be prepared for the Coroner.

In a statement Broadway Shopping Centre said: "Our condolences are extended to the family and friends of the security guard who lost his life in this tragic event."

- with Glenda Kwek