Mel Gibson‘s new Russian girlfriend is an ambitious social climber with a scandalous past, a string of ex-lovers and a penchant for older men, say sources close to her.

An Exclusive ENQUIRER investigation reveals that Oksana Grigorieva – the stunning, 39-year-old singer-pianist at the center of Mel’s $1 billion divorce – is the daughter of dirt-poor music teachers from the grimy industrial town of Saransk.

When she was 15, Oksana reportedly fell in love with James Bond star Timothy Dalton after seeing him on TV. Years later she bedded him and bore his son Alexander – but she refused to marry the 63-year-old actor because she didn’t like his “marriage contract.”

A close friend described her as “beautiful and talented, but also a force to be reckoned with.”

Oksana married for the first time at age 19, but the union ended quickly. A second marriage also ended within six months. The beauty later had a relationship with a much-older Russian violinist.

Oksana migrated to England to seek fame as a model and actress – and developed a pattern of using men as stepping stones, say friends.

“She left a young man when she met Timothy Dalton and then moved up in the celebrity world to Mel Gibson,” declared Dame Elisabeth Hoodless, the head of Britain’s leading volunteer agency, who gave Oksana her first job in England.

Dame Hoodless told The ENQUIRER her experience with the woman who hopes to be the next Mrs. Gibson turned sour.

“I hired her to look after my elderly parents when she first came to Britain. She was supposed to be looking after them, but instead she would make them – two elderly people – run errands for her!”

Oksana’s friend added: “If Oksana has decided she wants Mel to be her husband, she’ll work relentlessly to become the next Mrs. Gibson.

“Oksana is definitely a woman who knows what she wants – and goes after it!”