The 55-year-old underwent surgery on Tuesday night after antibiotics failed to fix an infected valve leading to his heart, daughter Kayla said.

Fenech, now a trainer, was in Thailand for a training camp when he fell ill.

Kayla said the surgery was a success but she was yet to speak with her father, who will now miss daughter Jess' wedding.

"We landed and literally rushed to the hospital and got there, thank God, he was feeling okay, I guess he was scared. It was good to speak to him and give him a hug before he went in," Kayla told the Nine Network.

"We've never seen him like this before so it's hard for all of us and especially he's definitely not attending my sister's wedding, it's a really hard time."

Kayla said Fenech was not aware of the severity of his heart problem and had ignored his discomfort for several days before surgery.

Wife Suzee is also reportedly in Thailand with her husband.

Fenech earlier released a video explaining his illness.

"I've got some pretty bad news, I've got an infected valve that's connected to my heart," an emotional Fenech said in a video by Boxing Epicentre.

In his 33-fight professional boxing career, Fenech won 29 bouts, including 21 knockouts, and was a world champion in three weight divisions.

Australian Associated Press