China's invitation to Prime Minister Najib Abdul Razak was also extended to his family, said Rizal Mansor, the aide to the premier's wife Rosmah Mansor.

"The Chinese government invited the PM and his family for this official trip.

"Those familiar with Chinese culture would know that this is a standard custom of China's top leaders who emphasise on strong personal and family relationships with their close counterparts.

"This custom of family relationships is given even greater significance due to the ancient Chinese proverb of '飲水思源' - literally 'when you drink water, think of its source'," said Rizal in a post on Facebook.