Detectives are carrying out an operation at the home of troubled singer Amy Winehouse in northwest London.
Scotland Yard confirmed there was police activity at the Camden house.
A spokesman said: "We can confirm there is police activity as part of an ongoing police operation."
The Back To Black singer is reported to have recently been battling drug addiction and cancelled a series of European gigs earlier this year after suffering from "severe exhaustion".
Last month she and her husband, Blake Fielder-Civil, were held overnight by police in Norway for possession of drugs.
Three police officers were standing outside her house while others were believed to be inside the property.
Ms Winehouse is thought to have left her house this morning and her husband left earlier this afternoon.
The only other activity in the street was a gathering of about 15 paparazzi photographers.
Officers could be seen moving in and out of the back door of the property, but neighbours refused to comment on what had been happening.
A spokesman for Ms Winehouse denied the police activity had anything to do with drugs and said the singer had not been arrested.
"The only thing I can tell you is that it has nothing to do with drugs and that Amy is fine and she has not been charged or arrested," the spokesman said.
He would not say where the singer was this evening.
A Scotland Yard spokesman confirmed no arrests had been made as part of their operation.