— With AAP.
The baby, who was 54cm long and weighed in at 3.9kg, is reportedly named after Joyce’s grandfather, Thomas.
The couple already have a baby son, Sebastian, who was born 14 months ago.
Vikki Campion and Barnaby Joyce were interviewed about their affair on Sunday Night. Post continues after video.
Joyce also has four daughters from his marriage with his now estranged wife Natalie – Bridgette, Julia, Caroline and Odette.
The couple’s second pregnancy was announced after a “close friend of the family” told The Sunday Mail that they were expecting a boy.
“The name is already picked out — Thomas, after Barney’s grandfather,” said the anonymous source.
“They plan to include Timothy, Barney’s youngest brother who sadly died last June after a brave battle with lung cancer. Tim was only 42 and has a gorgeous wife and three young children. His death really rocked Barney (as he is known to family and friends).”
The New England MP resigned as deputy prime minister and Nationals leader early last year after revelations surfaced of his affair with his former staffer.