An inquiry is to be carried out into the leaking of a string of high-profile honours from the the New Year list before they were officially announced.
Awards for actors John Hurt, James Corden and Sheridan Smith, as well as Joan Collins and Esther Rantzen were all revealed in reports days before they were formally published tonight.
Recipients normally learn they are to be honoured weeks before the list is published, but they are sworn to secrecy.
Sir Bob Kerslake, the outgoing head of the Civil Service, said he was "concerned" by the "highly regrettable" leaks.
He said: "I think it's unfair on the individuals who are asked, indeed instructed, to keep the fact that they are recipients of awards confidential.
"I can't comment on where they are coming from. We will look into it, I'll leave it at that."
High-profile honours have frequently been leaked ahead of previous lists, but Sir Bob said they will look into the "extent of leakage" this year.
He said:"There have been leaks in the past but there was, on this particular occasion, a significant number and that's the point we will look into."
He also highlighted the issue of individuals being wrongly named as receiving honours.
"It's particularly unfair when names get quoted in the papers who then subsequently aren't on the list. In every sense it's highly regrettable and we will look into this," Sir Bob said.
It comes after reports that Jonny Wilkinson was set to receive a knighthood, before it emerged that he is not included in this year's list.
The rugby star appeared to heighten the speculation in a message he posted on Twitter on Monday night.
He wrote: "So many more deserving amongst u who won't get recognition. To you I say thanks 4 the lessons in life. 4 the messages - u guys are incredible."