Zak Brown admits he is among those who are "concerned" about the ever-closer relationship between Red Bull's two Formula 1 teams.

We reported just before Christmas that rival teams may even begin to push for the energy drink brand to sell Alpha Tauri, as Red Bull seeks greater synergies between its two outfits.

Brown, CEO of McLaren, declared this week: "I am concerned about the Alpha Tauri-Red Bull alliance."

The American said he has heard that Alpha Tauri will be moving much of its operations from Italy to be closer to Red Bull Racing in Milton Keynes, UK.

"So this A-B team and co-ownership, which is a whole other level of A-B team, is a big concern to us and the health and fairness of the sport," Brown insisted.

"It's pretty much not allowed in any other form of major sport, and I'd like to see us as an industry focus on that before it gets to a level of being where F1 once was, which was very out of balance."

Even top figures at the FIA have admitted they are keeping a close eye on Red Bull-Alpha Tauri style team alliances.

"The regulations regarding what is allowed and what is not must be adjusted," Brown says. "They were written in a time without budget caps.

"They wanted to help small teams because the difference between a Mercedes and a minor team was unbridgeable. With a cost cap, this is no longer necessary. On the contrary," he added.

"It offers much greater benefits to the A team and the B team than before. And F1 needs ten independent constructors."