Bobbi Kristina Brown and her boyfriend Nick Gordon collect guns.

The 19-year-old actress — the daughter of the late Whitney Houston, who died in February this year — took to social networking site Twitter to reveal she and Nick have "always" loved to purchase firearms after he tweeted of picture of himself driving one-handed while holding a large revolver in the other hand.

She wrote: "I & @nickgordon loveUall! Ha thank4ur love & support! We R both collectors of guns actually, We always have been. Lol. (sic)"

Following a barrage of online criticism about the image, 22-year-old Gordon — who Houston  adopted 10 years ago after his father was sent to prison, although the adoption was never made official — removed the picture of his registered gun from Twitter and has now apologised for uploading it. 

In a series of tweets, he wrote: "I apologize for posting a picture with my registered gun. That's not what we stand for and I didn't mean harm by it, it's a collectors item

"Moving forward I'll obviously be more mindful/thoughtful about how my actions influence others and reflect on the ppl I love and care about (sic)"

Gordon has grown closer to Brown following Houston's death and the pair are currently filming their own reality TV show, The Houstons: On Our Own - which is due to premiere next month - in Hawaii.