Leona Lewis meets Sam Bailey for X Factor rehearsal

Leona Lewis has paid a visit to Sam Bailey before this week's X Factor show, sparking speculation that Sam may perform one of the former winner's hits.

This weekend sees the ITV singing contest's 10th anniversary celebration, where contestants will sing hits by the show's biggest stars and there will be some special appearances from X Factor alumni.

Bleeding Love pop star Leona, who won in 2006, tweeted a black and white photo of herself with Sam, standing by a piano and what appears to be a print out of song lyrics.

She captioned the photo: "Had a little visit with this lovely lady today @SamBaileyREAL."

Performances over the weekend will come from former X Factor stars Olly Murs, One Direction and JLS.

Patrick McLennan is a London-based journalist and documentary maker who has worked as a writer, sub-editor, digital editor and TV producer in the UK and New Zealand. His CV includes spells as a news producer at the BBC and TVNZ, as well as web editor for Time Inc UK. He has produced TV news and entertainment features on personalities as diverse as Nick Cave, Tom Hardy, Clive James, Jodie Marsh and Kevin Bacon and he co-produced and directed The Ponds, which has screened in UK cinemas, BBC Four and is currently available on Netflix.

An entertainment writer with a diverse taste in TV and film, he lists Seinfeld, The Sopranos, The Chase, The Thick of It and Detectorists among his favourite shows, but steers well clear of most sci-fi.