A suit worn by pop star Sir Elton John, shoes worn by actress Sienna Miller, and a script of acclaimed film The Queen signed by its star Helen Mirren are going under the hammer to raise cash for Oxfam's Darfur and Chad appeal.

Oxfam, based in Cowley, Oxford, is organising its biggest celebrity and public auction to alleviate suffering in the region.

Sir Elton wore the tailor-made Donatella Versace suit to his famous White Tie and Tiara Ball. A black Dolce & Gabbana jacket worn by Chris Martin during Coldplay's A Rush Of Blood To The Head tour is also up for grabs.

Other items include a pair of gold-coloured designer shoes signed by Factory Girl star Miller and a Tracey Emin pencil sketch.

The red dress worn by Corinne Bailey Rae in the Put Your Records On video has been donated, along with a limited edition, signed Gorillaz print.

The public can also offer their own items, such as books, clothes and antiques, in the online eBay auction to raise funds for Oxfam's work.

The appeal for Darfur and Chad has raised £800,000 since its launch on April 16.

It is hoped that the auction, which runs until next Friday, will generate a further £500,000.

Sir Elton said: "I'm delighted to donate this suit that was custom made by Donatella Versace for me to wear to the White Tie and Tiara Ball in 2000, and hope it raises lots of cash for the people of Darfur who have already suffered too much."

Oxfam will be adding more items to the auction, including the back of the chair used and signed by Bill Nighy on the set of Pirates Of The Caribbean, a guitar signed by rock band The Kooks, a dress from model Sophie Anderton, a pair of underpants signed by band Razorlight, signed photographs of pop star Jamelia and concert tickets to see Jon Bon Jovi and Justin Timberlake.

Jamelia said: "As a mother I can't imagine how any parent can cope looking after their children in such appalling conditions.

"I hope donating these pictures will raise as much cash as possible."