David Cameron confirmed today that he did ride a horse which was lent by police to former News of the World and Sun editor Rebekah Brooks.
The Prime Minister apologised for allowing a "confusing picture" to emerge over recent days about his direct connection with the animal.
He told reporters that the horse, Raisa, was among his mounts when he rode, before becoming Prime Minister, with Mrs Brooks's husband Charlie, a friend since they attended Eton school.
"I have not been riding with him since the election. Before the election, yes, I did go riding with him," he said at a press conference in Brussels.
"He has a number of horses and, yes, one of them was this former police horse Raisa which I did ride.
"I am very sorry to hear that Raisa is no longer with us and I think I should probably conclude by saying I don't think I will be getting back into the saddle any time soon."
The question of whether Mr Cameron rode Raisa became the subject of Westminster speculation this week after the loan by Scotland Yard to the ex-tabloid editor was made public.
After initially declining to directly answer questions, Downing Street aides conceded last night that the premier "probably" had mounted the ex-Metropolitan Police horse.
That came shortly after Number 10 had been forced to retract an earlier briefing that he had ridden with Mr Brooks after taking office in May 2010.
His spokeswoman also said that while he had "no recollection" of ever having ridden with Mrs Brooks, that could not be ruled out.
The case has refocused attention on the relations between politicians and newspaper executives, which Mr Cameron has admitted became too close over recent years.
Asked whether the case was emblematic of those overly close ties, Mr Cameron said: "I have known Charlie Brooks, the husband of Rebekah Brooks, for over 30 years.
"He is a good friend and he is a neighbour in the constituency. We live a few miles apart."
Details of the two-year loan of the horse were given last month to the Leveson Inquiry into media ethics which is currently scrutinising relations with the police.
Mrs Brooks, who resigned last year as chief executive of News International amid the furore over phone-hacking allegations, "fostered" the horse after it retired from active service in 2008.
She remains on bail after being questioned by detectives, days after resigning last summer, on suspicion of phone hacking and corruption.
She and her racehorse trainer husband paid food and vet bills until Raisa was rehoused with a police officer in 2010 - months before fresh investigations into illegal activities at the News of the World.
The force said the horse was returned in a "poor" condition and later died of natural causes.
Mr Cameron said in an interview yesterday that he had ridden once since becoming Prime Minister but Number 10 has declined to discuss the circumstances.