Plan B has secretly became a father for the first time.

The 'She Said' rapper's long-term girlfriend gave birth to their daughter ''last year'' and he is ''proud'' after they spent their first Christmas with the new arrival.

He told The Sun on Sunday newspaper: ''My girlfriend and I had a baby girl last year.

''Mother and daughter are both fit and well and I'm a proud and happy father - especially after having just enjoyed our first Christmas together.''

The musician - whose real name is Ben Drew - has kept his relationship and family private, and while it was a ''surprise'' for them, he is embracing his responsibilities as a parent.

An insider said: ''It was a surprise to both of them when Ben's girlfriend discovered she was pregnant but Ben is over the moon at becoming a father.

''They've been dating for a couple of years and having a baby has brought them even closer.

''Ben may have a bad-boy image but he makes a great dad and is happy to get stuck in. He is even getting good at changing nappies.''

Meanwhile, fatherhood hasn't made him ''soft'' musically, and he is said to have been telling friends his next album will still be ''no-holds-barred''.

The source added: ''He has been playing [his daughter] some of his tracks to see if she likes them. His songs are known for being pretty gritty so he's been playing her the music without any lyrics.

''But he's joked with friends that becoming a dad hasn't turned his music soft and he's definitely planning another no-holds-barred record.

''2014 is going to be another big year for him - he's very content and can't wait for everyone to hear his new material.''