Manchester United boss Sir Alex Ferguson is having second thoughts about a deal for Gremio starlet Douglas Costa.

The News of the World says Ferguson might pull the plug on a deal for Douglas Costa over concerns about the player's private life.

The Gremio midfielder, 18, was arrested by Brazilian police earlier in the week for driving without a valid licence. He has already been fined by police and has had yet another dressing-down from club officials.

It is the latest incident in his controversial career and Manchester United have been made aware of an increasingly long list of off-field problems.