The son of retired solicitor Peter McCarthy has spoken for the first time since his father was found beaten to death at South Coogee, remembering him as "a larrikin and loving" family man.

"He was a great dad and an amazing grandfather to my two sons," James McCarthy said.

"A typical Aussie larrikin I guess you could say but with a well-mannered twist – he was always trying to help whoever he could help," he said.

Mr McCarthy paid tribute to his father the day after Sydney homicide detectives arrested Narelle Fiona Smith, 46, and charged her with murdering the 77-year-old sometime between December 16 and 20 last year.

"He's a 78-year-old man -who was nice to everyone and did whatever he could to look after anyone so you just don't think that something's going to happen to him," he said.

Ms Smith has denied having anything to do with Mr McCarthy's death and told 9News: "I didn't do it" as she was led out of her South Coogee unit, next door to where Mr McCarthy lived.

Mr McCarthy was last seen on December 16 at Club York in Sydney's CBD where he regularly visited.

Four days later his ex-wife discovered him dead after being savagely beaten.

Police are investigating whether robbery was a motive because Mr McCarthy's brown satchel and phone were missing from his unit.

Ms Smith has also been charged with stealing Mr McCarthy's Opal card and is accused of using it on two buses the day Mr McCarthy's body was discovered.

The 46-year-old was due to face Waverley Local Court today but she didn't apply for bail and it was formally refused. The case returns to court in March.