Amy Winehouse was spotted shopping for alcohol and sweets yesterday instead of joining her pop contemporaries at a photocall for Friday's Nelson Mandela concert.

Although the troubled star confirmed she will sing at Mandela's 90th birthday concert - despite being diagnosed with early stages of emphysema - her snub will no doubt unsettle organisers and fans ahead of the highly-anticipated gig in London's Hyde Park.

Should you be elsewhere? Amy Winehouse snubbed the photocall to visit her husband in prison and buy alcohol

The 24-year-old was released from hospital on Monday after doctors confirmed she has scarring of the lungs which can cause emphysema, but it is treatable.

Despite pledging to honour her live commitments at both Glastonbury and the Mandela concert on Tuesday and spending an hour-and-a-half in rehearsals since leaving the London Clinic, Winehouse was a no-show on Thursday.

Instead she visited her husband Blake Fielder-Civil at London's Pentonville Prison, before stopping off at an off licence for some Jack Daniels whisky and vodka and a packet of sweets.

She also picked up a box of Euro 2008 stickers - perhaps a gift for the many young fans who regularly wait outside the singer's north London home.

Checking out the weeklies: Amy Winehouse scans the gossip magazines for her picture

Meanwhile, Michael Eavis has given the clearest hint yet that Winehouse will be well enough to perform at this year’s Glastonbury festival.

The festival’s 72-year-old founder revealed last night that he was looking forward to seeing Miss Winehouse’s scheduled performance on Saturday more than any other.

An offer of a helicopter to fly her in and out of Glastonbury to assure her the minimum of stress has also been put in place.

The Mandela concert was in crisis after it was revealed that both Dame Shirley Bassey and Amy were set to be no-shows.

Dame Shirley has been advised by doctors not to travel following her emergency stomach operation, her spokesman said.

The 71-year-old singer, who lives in Monaco, had been expected to recover in time for Friday's event.