Pixie Lott has lost her mobile phone.

The 24-year-old singer misplaced her device when she accidentally left it in the back of a taxi.

Taking to Twitter, Pixie - who often refers to her fans as Crazy Cats - wrote: ''Cats! I'm a cat without a phone cos somebody left it in a black cabbie - some things never change (sic).''

However, it isn't all bad news for Pixie - who recently dyed her blonde hair blue - as she has signed up to perform at an upcoming charity event in London.

After spending some months in Los Angeles, working on her new album, Pixie is currently back in London and will be among the performers at the British Heart Foundation's (BHF) Tunnel of Love event on November 11th at London's Victoria & Albert Museum.

Pixie's performance will help to raise funds for the organisation's Mending Broken Hearts Appeal.

She said: ''I'm delighted to be performing at Tunnel of Love this year and supporting the BHF's life saving work. Heart failure is a devastating and incurable condition affecting around half a million people in the UK.

''The money raised from Tunnel of Love will help fund vital research that will bring new hope to people living with this debilitating condition.''