Chris Froome reportedly refuses to give his backing to Team Sky boss Dave Brailsford

Team Sky's attempt to present a unified front in the face of growing controversy was dealt a blow on Tuesday as star rider Chris Froome reportedly declined to sign a joint statement supporting team manager Dave Brailsford.

On Monday night, a number of Team Sky riders - not including Froome - took to Twitter to give their support to Brailsford, with the team planning to put out a joint statement of support on Tuesday.

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However, according to the Telegraph and other media outlets, Froome declined to sign the statement (which was then shelved), choosing instead to take to Instagram to share a photo of himself and his son with a giraffe in South Africa.

Froome's silence comes as his team continues to fight back in the controversy surrounding the mystery package delivered to the team at the 2011 Critérium du Dauphiné and the use of therapeutic use exemptions before major races.

Although there was not statement from the riders on Tuesday, there was a lengthy document issued by the team itself, attacking "inaccurate" and "simply untrue" assumptions made over the past few months.

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As for Froome, he last spoke at length about the issue in January, when he sought to distance himself from Brailsford and the team, asking people to judge him on his values, rather than what was going on around Team Sky.