Sources told the site: "De Niro and Grace are breaking up".
Robert De Niro. Credit PA
ET reports that the outspoken actor and his philanthropist wife have split.
The "Goodfellas" star is said to have split from his spouse and they are expected to make a formal announcement in the coming weeks.
14 years ago, in 2004, the duo renewed their vows in front of friends, family and other celebs.
Several social sources have noticed in recent times that De Niro has been appearing in public at events that he would otherwise have been at with 63 year old Hightower.
In news that broke last night, it looks like the pair are no longer living together with multiple publications stating that the 75-year-old actor is living separately to his wife and seven-year-old daughter, Helen, as they go through the process of separation. But in a shocking twist of events, the two chose to reignite their romance before divorce papers could ever be signed. I saw what happened, I should have done something and I didn't'. He is also the father to two children by model Toukie Smith, who he dated between the two marriages.
De Niro spoke about his feelings on marriage in a 2013 interview with Katie Couric. However, the newlywed bliss was brought to an abrupt end when De Niro filed for divorce in 1999.
The star of The Godfather Part II said that the secret to a happy union involved 'a lot of give and take, standing your ground, because then you keep the respect you started out with'.