Washington, Sept 10 : Robbie Williams has become a recluse in recent months, according to his friends in Los Angeles.
The pop singer was previously a regular on the city's nightclub circuit, but has been shunning his old associates and spending more time at home with girlfriend Ayda Field.
Fans have been left worrying that he might never take to the stage again, having last performed live two years ago.
The former Take That singer even shunned the MTV Video Awards in Los Angeles last week.
Williams' withdrawal from life comes as his obsession with alien life has intensified.
He has also piled on the pounds and grown a shaggy beard.
His last album 'Rudebox' was slammed by critics when it was released in October 2006.
The attacks and disappointing sales were said to have knocked Robbie's confidence and left him wondering whether he has any future in music at all.
He had to cancel the Asian leg of his Close Encounters world tour in 2006 citing stress and exhaustion.
"Robbie has battled a lot recently, and it's left him very wary of new people and going out generally," the Daily Star quoted a source, as saying.
"At the moment, it's like he has been kidnapped. He just isn't around," the source added.