Manchester City's Brazilian striker Robinho has left the club's training base in the Canary Islands and could face disciplinary action, the Citizens' executive chairman Garry Cook said on Tuesday.
"I do know Robinho is not at the training centre in Tenerife," Cook told the BBC.
"If he has left the training ground it is a breach of club discipline. I am waiting for a full debrief."
Big-spending City made Robinho British football's record signing when they paid Real Madrid £32.5 million for the 24-year-old in August last year
He has scored 12 goals for his new club and become a favourite of the club's fans.
The Robinho mystery comes hard on the heels of the news that another Brazilian, midfielder Kaka, will not be moving to Eastlands for a reported world record transfer fee, preferring instead to stay at AC Milan.