Illusionist David Blaine may have to pay the cost of policing his starvation stunt in London when it ends.
Blaine faces further torment from the public during his 44-day stunt
Police say dealing with the stunt near Tower Bridge - where the showman is suspended in a plastic box for 44 days - has proved costly.
"We have concerns about the public order situation around what he is doing
down there," said Metropolitan Police Commissioner Sir John Stevens.
He said the stunt was "an example of how these things can escalate".
"We have asked the people who have been staging the event to pay for the policing. It is important to say that
there has been a considerable expense," Sir John said.
Blaine, 30, is currently 21 days through his stunt, in which he will be devoid of human contact and will not ingest anything except water.
He has been taunted by members of the public and several tabloids, who have played tricks ranging from stripping off to grilling food below him.
One man was last week charged withy criminal damage after trying to cut off his water supply, while former Beatle Sir Paul McCartney was involved in a scuffle with a photographer at the stunt last Friday.
Remote control burger
The Sun newspaper had reported that a website for gay men has asked its users to throw sausages at his box.
A member of the public and a security guard had also traded blows at one stage after the guard accused the man of throwing missiles at the box.
The magician has also been taunted by people hitting golf balls at his box, been woken by drumming and a burger has been flown up on a remote-controlled helicopter.
Blaine's exploits are being filmed for TV shows on Channel 4 and Sky One.