Amy Winehouse in London. (Reuters)

London, April 26 (Reuters): Grammy-winning singer Amy Winehouse was cautioned for assault and released without charge today after spending the night in custody, police said.

A man said he was assaulted in the early hours of Wednesday in north London and the singer presented herself at a central police station in central London yesterday for questioning.

Winehouse admitted common assault after slapping a man with her open hand and accepted the caution, her spokesman said.