Rap star Sean Combs has been asked in court to remove his alias "Diddy" from websites after an earlier settlement with a musician known by the same name.
Combs has changed his alias several times
The rapper settled out of court with Richard "Diddy" Dearlove last year, agreeing not to use the name in the UK.
Mr Dearlove's lawyer, Iain Purvis QC, told London's High Court that Mr Combs had made changes to two of his websites but "Diddy" was still used on others.
He said Mr Combs had refused to make changes to sites not under his control.
"We want him either to use a neutral name like P Diddy or to shut them down," he said.
Mr Dearlove, best known for his remix of the Blondie hit Atomic, has traded under the name "Diddy" since 1992.
The 41-year-old wants Mr Combs to erase "Diddy" from sites including YouTube and MySpace.
Mr Purvis said it could be difficult for Mr Combs to do this but that it was his responsibility.
"What we say is he has given these undertakings and it is up to him to make sure they are complied with."
Mr Purvis said that in keeping with an earlier agreement, Combs made sure UK visitors to his own international website www.diddy.com were diverted to a British site where "Diddy" was not used.
Under the settlement with Mr Dearlove, Mr Combs is allowed to use "P Diddy" in the UK and "Diddy" outside the UK.
If the judge rules that Mr Combs has breached the agreement, Mr Dearlove will ask for an injunction barring him from continuing to do so. Mr Dearlove could then seek damages.
Mr Combs, 37, changed his name from Puff Daddy to P Diddy in 2001, later dropping the "P" from his name in 2005.
Sites like YouTube and MySpace have proved useful marketing tools for musicians - Mr Combs's MySpace profile has been visited 10 million times.
The hearing continues.