HONG KONG - A 61-year-old former police officer was jailed for 16 years and eight months by a court on Thursday (Feb 1) for sexually assaulting his two daughters, causing one of them to become pregnant, Hong Kong media reported.

He started to sexually assault his daughters in 2013 during play, and when he failed to rape his elder daughter, 12, he went on to rape the younger one, then 10, the South China Morning Post reported.

He recounted how his daughters were laughing at the time as he did not explain to them what he was doing, the Post reported.

The sexual abuse lasted for three years, and came to light on Dec 17, 2016, when the elder daughter, 15, suffered severe stomach pain and was taken to hospital. She was found to be around 30 weeks pregnant, and gave birth on that same day.

On Thursday, the man appeared in the High Court and pleaded guilty to eight counts of incest, rape, attempted rape and indecent assault. Neither he, nor his daughters, can be identified for legal reasons.

Deputy High Court Judge Brian Keith said the case was "a breach of trust of the very worst kind", the Post reported.

"Incest is one of our society's great taboos... It strikes at the very fabric of family life, especially when there is, as here, such a disparity of age between you and your daughters," the judge said, noting that the man had abused his daughters' trust in him, despite being fully aware of their unwillingness.

Acting senior public prosecutor Lenny Cheng said the elder daughter had tried to resist by locking her bedroom door, but her father would enter with his key. She tried to twist and turn in bed to avoid him but he pinned her down, the Post reported.

The father had said upon his arrest: "I was wrong, I had done something very wrong and made her pregnant."

He also confessed that he liked to watch pornographic movies depicting incest and had been watching them before he raped his daughter.

The judge said he had considered a heavier punishment, but decided against it as there was no evidence to suggest the man posed a threat to other women.

With a starting point of 25 years in jail for the man, the judge reduced the sentence to 16 years and eight months, after considering his guilty plea.

The guilty plea ensured the two girls did not have to testify in court.

The man, who was a police officer in the 1970s, quit the force in 1984 and became a cab driver. He had prior convictions for dangerous driving and overcharging passengers, the Standard daily reported.

He remarried after a divorce, and had the two daughters with his current wife. The four of them lived together with a stepdaughter on monthly Comprehensive Social Security Assistance of HK$8,000 (S$1,343).

From 2014 to 2016, the man raped his elder daughter four times without wearing a condom, and a rape in 2016 made her pregnant. He also sexually assaulted the younger daughter during the period.

The judge, citing a psychological report, said the impact on the two daughters was beyond estimation, the Standard reported.

The younger daughter, now 14, has refused to talk to a clinical psychologist.

Her older sister spoke little of what happened, the Post cited a source as saying. Her child has been given up for adoption, and is said to be healthy.