Opera singer Russell Watson is currently undergoing ‘complex surgery’ to remove a brain tumour, it has been confirmed.

The popular tenor is being treated at the private Alexandra Hospital in Cheshire, where his operation was due to begin at 7.30am on Thursday morning.

He was taken there after falling ill in a recording studio on Wednesday.

Russell had surgery to remove a benign brain tumour in September 2006 after falling ill in the US.

“This is a new tumour and a far more aggressive tumour than the one before,” said the 40-year-old’s agent, Richard Thompson.

And a message on Russell’s official website confirmed ‘with much sadness’ that the star was ‘in a critical condition’.

It continued: “All our hopes, prayers and wishes are with him and we hope to bring more uplifting news later on today after he is out of the operating theatre.”

A spokeswoman for the hospital in Cheadle confirmed that Russell was admitted on Wednesday afternoon.

“Russell Watson is at the Alexandra Hospital. He came in yesterday afternoon. No other information can be given at this time.”

She said the hospital was used to carrying out ‘complex surgery’.

The Salford-born tenor, who was a factory worker before he turned to singing, has sold more than four million albums worldwide.

His latest album, Outside In, is due for release on November 26.