Amy Winehouse may be forced to cancel two major appearances this summer amid fears she has contracted a chest infection.

The singer, 24, who is in hospital, was said to have been coughing up blood from a and suffered dramatic weight loss  - key indicators of TB.

But a spokesman for Amy claims she is simply suffering from a chest infection and does not have tuberculosis.

She has been put on a drip at the London Clinic in Harley Street and her father Mitch, who took her to hospital after she collapsed on Monday, remains at her bedside.

Amy Winehouse was taken to a clinic after fainting on Monday

A close friend said: 'Doctors are still struggling to control her heartbeat but the chest condition has been really worrying them.

'She'd been suffering horrible coughing fits and hurling up blood for a while but refused to be examined. Doctors are doing more tests to be certain. The last thing she needs is to be wheeled on stage. She needs a rest.'

Winehouse, who has battled heroin and crack cocaine addiction, has lost her appetite and has an irregular heartbeat.

But her spokesman insisted she still intends to play Nelson Mandela's 90th birthday concert in Hyde Park on 27 June and the Glastonbury festival the following day.

The singer's dad Mitch remains by her side

He said: 'At present, she still intends to perform at the two scheduled dates next week.

'However, a decision will be made entirely upon the advice of her doctors.'

Winehouse was admitted to the private clinic after she collapsed at home in Camden.

Last August, the star was hospitalised after a drugs bender and doctors are examining if the episodes are linked.

A spokesman for Winehouse said: 'They are still doing tests and scans. If it's something not-so-serious then she will perform.

'It's the sort of thing she always wants to do if she can, but we will listen to the doctors.'