Gossips believe the substance is cocaine.

During her erratic performance at the Empress Ballroom in Blackpool, Amy told the audience she had missed her evening phone call to husband Blake, who's currently in custody at Pentonville prison.

'He would have loved to have been here. I spoke to him last night but I can only call either before or after EastEnders,' Amy explained.

The star began rambling and became less coherent as the night wore on.

'She said she was going to introduce her band then walked off stage, so they had to do it themselves,' an onlooker tells the Daily Mail.

After the show, paparazzi snapped the singer with what looked like a smudge of powder up her nose.