Pyongyang, Nov 11 (IANS): A North Korean man has pleaded with Chinese President Xi Jinping not to forcibly repatriate his wife and young son, saying they face imprisonment or death if sent home, a media report said on Saturday.

The woman and her four-year-old son are understood to have been among a group of 10 North Koreans who were arrested in a raid on a safe house in China's Liaoning province on November 4, the BBC report said.

The man, who asked to be identified only as Lee, fled to South Korea in 2015. He recorded his plea in a video message, which was passed to the BBC.

He said his wife and son would "either face execution or wither away in a political prison camp" if sent back to North Korea.

"I wish China's Xi Jinping and US President Donald Trump would think of my child as their grandchild and send my son to the free country, South Korea.

"Please help us. Save my family from repatriation. As the father, I beg the two leaders to help my family. Please help us," he added.

Meanwhile, China's Foreign Ministry spokeswoman Hua Chunying said in a news briefing that she was unaware of details of the case, the BBC reported.

She said China consistently upholds the handling of such matters in accordance with domestic and international law and humanitarian principles.

The arrests come amid a crackdown by China on North Korean defectors. Chinese security services have apprehended at least 49 North Koreans in the three months between July and September, according to the Human Rights Watch.

At least nine of those arrested over the past three months are known to have been forcibly repatriated back to North Korea, the rights group said.

The number of North Koreans defecting to South Korea dropped by 13 per cent this year, according to officials in Seoul's Unification Ministry.

From January to August, 780 North Koreans escaped to South Korea, it added.