Hugh Grant, the British actor, is “delighted” at becoming a father for the first time at the age of 51, his spokesman said on Tuesday.

The Notting Hill star welcomed a baby girl in late September after a “fleeting affair” with an unnamed woman, believed to be a Chinese actress 19 years his junior.

While the identity of the mother has not been disclosed nor details of the couple’s relationship, the star has been linked to Tinglan Hong.

On the day that the baby is said to have been born, Grant was reported to be at the Labour Party conference in Liverpool.

On Tuesday night, a spokesman for the Bridget Jones and About a Boy actor confirmed the news but declined to say who the baby’s mother was.

"I can confirm that Hugh Grant is the delighted father of a baby girl," she said.

"He and the mother had a fleeting affair and while this was not planned, Hugh could not be happier or more supportive.

"He and the mother have discussed everything and are on very friendly terms."

Hong, 32, was reported to have been showing a small baby bump in April when she was photographed leaving Grant's ￡3 million home in Chelsea, west London.

US reports said Grant was no longer in a relationship with the mother of his child. The actor, one of Britain's most successful, is known for being publicity shy and rarely discusses his private life.

British reports suggested the baby was born by Caesarean section on September 26 at the Portland Private Hospital, central London and used the name "Sophie" Hong during her stay.

Grant is not reported to have been present at the birth but is instead believed to have spent around half an hour with her the following day before heading to Scotland to play in a golf tournament.

The actress recently moved from her home in Merton, south London to an address closer to the actor's home but the baby has yet to be registered at Westminster Register Office, the Daily Mail reported. Legally it has to be registered by Monday.

The actor has never married but in a 2007 magazine interview, he spoke of his desire to be a father.

(Read by Nelly Min. Nelly Min is a journalist at the China Daily Website.)