Britney Spears' team have been briefed to cover up her plans to lip-sync during her Las Vegas concert residency.

The 'Toxic' hitmakers' managers have created a ''cheat sheet'' of answers to be given to curious media and fans about her two-year 'Britney: Piece of Me' shows in the US gambling capital, and the document has now been obtained by the New York Daily News newspaper's Confidenti@l section.

According to Confidenti@l, the paper features stock answers like, ''Yes! She will be singing live!'', ''Certainly she will be singing live!'', ''Yes, all vocals will be live!'' and ''No lip-syncing will happen at the show''.

However, the ''special notes'' section of the sheet indicates otherwise, and contains a note reading, ''All vocals will be pre-recorded.''

It adds that the ''live'' band ''will be pre-recorded also.''

The document warns staff at Planet Hollywood to ''try and stay in the margins of the provided answers and refrain from elaborating replies''.

The pop princess will kick off her residency on December 27 and is reportedly being paid $15 million a year.

Rumours of a cheat sheet first emerged in September, but Britney's team have vehemently denied suggestions she will be lip-synching.

A source said at the time: ''Once Britney actually gets to Planet Hollywood everyone will have to sign confidentiality agreements, but right now I can tell you the answers we've been given to any and all questions are extremely sugar-coated.''