A man standing trial for killing his ex-girlfriend and stuffing her body into a wardrobe said he fathered a son while on the run in the mainland, the High Court heard yesterday.

In a recorded conversation with police played in court, Oscar Mok Chun-yin said he met his new girlfriend while on the lam, and she gave birth to a baby boy.

"He is two years old, and he won't have a complete family anymore," he told officers in January last year.

The 30-year-old Mok also apologized to his parents, grandparents, and the family of the deceased, Arbe Chan Man-yi.

"I am so sorry to all of them. I changed their entire future," he said.

Mok has pleaded not guilty to murdering Chan, 26, a Cathay Dragon flight attendant, at her Allway Gardens flat in Tsuen Wan on December 4, 2013.

He admits only to manslaughter as he did not intend to kill her, blaming his actions on uncontrollable rage.

The court had heard Mok went to Chan's home with hopes of getting back together after breaking up following a year of dating.

Chan offered him hope they would reconcile, but it was shattered when he learned she found a new boyfriend.

After the slaying, Mok fled to the mainland to mull over what he had done, and thought of surrendering at Mong Kok police station.

But he failed to go through with it, and instead took HK$100,000 from his parents before fleeing to Shenzhen.