Mel Gibson

The ‘Lethal Weapon’ star – who already has seven children with estranged wife Robyn - and Russian singer Oksana Grigorieva are said to be expecting their first child together in the autumn.

It has been claimed Mel, 53, has already told Robyn and their children the news, although it wasn’t well received.

A source told the National Enquirer magazine: "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.

"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."

Last month, the ‘Mad Max’ actor and 39-year-old Oksana – who already has a 12-year-old son with her ex-partner, former Bond star Timothy Dalton – made their first public appearance together.

The couple attended the Los Angeles industry screening for 'X-Men Origins: Wolverine' at Hollywood's Grauman's Chinese Theatre.

The actor held hands with Oksana as they walked the carpet and is determined to enjoy his life following the permanent split from Robyn, his wife of 28 years.

His representative said: "Mel has really been single for almost three years and it's nice to see him getting out and enjoying himself."

Robyn filed for divorce in April, citing "irreconcilable differences", and she is expected to get half his £450 million fortune.