Robbie Williams checked himself into rehab after allegedly telling mates if he didn't he'd kill himself.

An aide close to the star told the Daily Mirror that Robbie pleaded with him, "Get me help now or I might do something really stupid. I keep thinking of topping myself."

Another pal added, "We are desperately worried."

According to mates, the singer, who's become increasingly insular as his career has started to wane, sank into an even deeper depression after seeing his old band Take That hit the big time again, while his world tour was beset with problems and his latest album 'Rudebox' got critically panned.

Friends also say the 'Angels' crooner was distraught over Anna Nicole Smith's death, last week, and feared, as he is on a similar combination of prescription drugs, that he could go the same way as as the model.

The singer, who also suffers from insomnia, is said to have checked into the Cottonwood Clinic in Arizona after becoming addicted to popping more and more of his (controversial) anti-depressant drug, Seroxat, chain smoking and drinking high volumes of caffeine.

According to one report, before checking in, Rob was getting through 36 espresso coffees a day, 20 cans of Red Bull and chugging his way through 60 cigarettes.

But while mates worry for his fragile emotional state, the woman who knows him best - his mum, Jan - says his latest visit to rehab could be the turning point in in his life.

"I have known about Robbie's problems for some time and it has been very worrying," she said. "But from a mother's point of view, going into rehab is the best birthday present he could have given himself."

Here's wishing the Williams finally gets the help he needs...

'SLJ'