The publisher of the Mirror has apologised to Prince Harry for unlawful information gathering, at the start of a trial over alleged phone hacking.
EDnews informs via BBC that Mirror Group Newspapers (MGN) said it would never be repeated.
Lawyers representing Harry told the court he was subjected to the "most intrusive methods of obtaining personal information".
Harry is one of several high profile figures bringing claims against MGN.
Lawyers argue that executives at the company knew about widespread phone hacking but failed to act.
In a written submission, MGN - which also publishes the Sunday Mirror and Sunday People - said it "unreservedly apologises" for one instance of unlawful information gathering against Harry and said that the legal challenge brought by the prince "warrants compensation".
A private investigator was instructed by an MGN journalist at The People to unlawfully gather information about Harry's activities at the Chinawhite nightclub on one night in February 2004, Andrew Green KC said.
However, the subsequent article in The People is not one of the claims being brought by the prince, the barrister added.
MGN also denies allegations of voicemail interception in the cases being examined, including Harry's.
The publisher also claims some of the cases have been brought beyond a legal time limit.