A beaming Jamie Oliver could not wait to take his new born baby home as he posed for the first family photographs with the new arrival.

The celebrity chef, 41, and his wife Jools welcomed their fifth child, a baby boy, who the TV chef earlier told fans weighs the same as "16 packs of butter".

The couple were joined by their other four children at the Portland hospital in London.

They have three girls - Poppy Honey Rosie, Daisy Boo Pamela and Petal Blossom Rainbow - and a boy, Buddy Bear Maurice.

The new baby's name has not yet been revealed.

They did not know the sex of their unborn child and Oliver has previously admitted that "a bit more testosterone would probably be a good thing".

Earlier he posted a snap of the sleeping baby swaddled in a blanket on his Facebook page.

"And then this just happened guys!! It's a baby boy!! Everyone in the Oliver family is very surprised and beyond happy," he wrote.

"He arrived safely. Mum / @joolsoliver was really really amazing, unbelievably composed, natural birth and my two eldest girls got to come in at the very end as the baby was born which was amazing to witness. Very, very emotional."

The exhausted TV chef told fans: "8lbs (that's 16 packs of butter for you bakers out there). Anyway we're all hitting the hay. It's been a long day. Big love ... bless a little baby boy Woop Woop !!!!

"And love to all you mums out there how amazing you are it blows my mind ... Big love Jamie O."

Jools Oliver, 41, a former model who now has a children's clothing line, posted a picture of herself breastfeeding the baby on her Instagram page.

She said her two eldest daughters cut the baby's cord.

"Little baby boy Oliver has arrived. We are so very happy, blessed, grateful and totally in love all over again and so very proud of our two eldest daughters who cut the cord.

"Jamie was my hero. (no name yet)!!! XXXX," she wrote.

The Naked Chef has previously insisted that baby number five will be the couple's last.

"I mean, it's just getting ridiculous otherwise," he said. "This (baby) was not expected, I can't even believe I'm saying it. I think my own family were like 'Really?'"

He added: "I do what I'm told, but she's an amazing family-maker, and I just go with it!"

And the star has hinted that, just like his siblings, the fifth baby will have an unusual name, with the couple likely to go for seasons or "something floral or from the natural world".