Backstreet Boy AJ McLean 'enters rehab'

Backstreet Boys member AJ McLean has apparently returned to rehab.

The singer released a statement today saying that he has entered a treatment facility.

"For personal reasons, I’ve checked myself into a rehab clinic. With 2011 being a busy year for Backstreet, I want to be healthy and at my best," he said.

McLean explained that his rehab stint would not affect the Backstreet Boys' current tour plans.

The 33-year-old added: "Thank you for all of your support and respecting my family and friends’ privacy during this time."

The star entered rehab in 2001 to seek treatment for depression, an alcohol problem and anxiety, before returning in 2002.

McLean turned 33 on January 9.