Singer/songwriter Billy Preston is recovering from a serious infection of the sac encasing his heart.

The famed keyboard player, who became the fifth member of THE Beatles towards the end of their career, has been battling bad health since 2001, which resulted in him having a failed kidney transplant in 2002.

Preston, who performed on The Beatles' ABBEY ROAD album and toured and recorded with THE Rolling Stones, is "doing considerably better" after "a very catastrophic incident" last week (ends13JAN06), according to his manager JOYCE MOORE.

The 59-year-old's health worries were brought on by uncontrolled high blood pressure.

Preston has been on dialysis treatments ever since his transplant failed to take. He has decided not to undergo a second transplant operation.

Moore says he remains seriously ill.