Khan, 22, challenges for Kotelnik’s WBA light-welterweight title at the MEN Arena, Manchester, on July 18.
And Haroon, 18, has been hitting the headlines recently with a string of impressive amateur wins for England.
“I’ve been getting updates in the States about Haroon’s progression, and I’ve been doing some training with him since I’ve come back to the UK,” said Khan.
“He’s got so much talent and we’re always pushing each other on to do better, although I make sure I’m top dog!
“I don’t know if he’s going to go pro or not, but if he does then he’s good enough to win a world title.
“My dream is for us both to hold world titles at the same time and defend them at the Reebok Stadium in Bolton or in one of the big venues in Las Vegas.”
British boxing has seen plenty of brotherly glove over the years, and promoter Frank Warren’s current stable includes Kevin and Vinny Mitchell; Paul, Liam and Stephen Smith and Liam, Ryan and Michael Walsh.
“I don’t know if two brothers from Britain have ever held world titles before, so it would be great if Haroon and I could go down in history,” said Khan.
“But before we can even start thinking about that, I need to beat Kotelnik on July 18 at the MEN Arena.
“I read yesterday that he’s saying that I am underestimating him, but that’s not the case.
“I have trained for the hardest fight of my career, and I know that I will have to be at my very best to win.
“I have dreamed about winning a world title for a long time though, and it will be my hand raised later this month.”