Hongkong actress Grace Chan’s twin brother, Derek, has been spending more time in the spotlight recently, after starring in a make-up campaign alongside his famous sister.

Now, he’s even joined the world of social media, with Grace, 29, taking to her own Instagram to “welcome him” for “finally entering my [modern] 2020 world”.

For reference’s sake — Grace’s husband, 51-year-old Hongkong actor Kevin Cheng, joined Instagram two years ago, on October 5 2018.

And along with these comments were also those who wondered about Derek's ethnicity, with many saying he looks mixed race instead of Chinese .

It's not the first time the siblings have had their ethnicity questioned.

When Grace was crowned Miss Hongkong in 2013, some netizens accused her of going under the knife because she didn't look typically Chinese. There were also those who said that she was adopted by her Chinese parents.

At that time, Grace shared a picture of her and Derek from their childhood days, to quash the plastic surgery rumours. She also declared that she and her brother are definitely not adopted.

I think there [could have been] some mixed heritage on my maternal grandmother's side, but it skipped a generation, Grace said.

Photos: Grace Chan/Instagram, Derek Chan/Instagram