Mel Gibson's girlfriend is reportedly pregnant.

The star and songstress Oksana Grigorieva are expecting the baby towards the end of the year.

Gibson already has seven kids with his estranged wife Robyn, who reportedly did not take the pregnancy news well.

"In late April, Mel gathered his children at the family home in Malibu and broke the news that Oksana is pregnant, and he expects them to accept the baby as a new sibling," a source told the National Enquirer.

"They are quite upset. Even though Mel assured them the pregnancy was unplanned, they're furious with him, and say they're going to take steps to protect their inheritance, which they feel is in jeopardy."

Robyn filed divorce papers in April, claiming "irreconcilable differences" and stands to walk away with half of Gibson's $600-million fortune.

Grigorieva has a 12-year-old son with her former partner, 007 actor Timothy Dalton.