Oscar-winning actor George Clooney has called on media not to publish pictures of his children, to avoid putting them in danger.

The "Oceans 11" star says that, as a human rights lawyer, his wife Amal Clooney takes on evil-doers, making the couple's children potenial targets for retribution.

"The nature of my wife's work has her confronting and putting on trial terrorist groups and we take as much precaution as we can to keep our family safe," says Clooney's open letter, which was published in Variety.

"We cannot protect our children if any publication puts their faces on their cover."

The 60-year-old "Batman & Robin" star addressed his letter to "the Daily Mail and other publications," and said he was prompted to write after seeing photographs of actress Billie Lourd's one-year-old child online. Billie Lourd is Carrie Fisher's daughter.

"I am a public figure and accept the oftentimes intrusive photos as part of the price to pay for doing my job," the letter says. "Our children have made no such commitment.

"We have never sold a picture of our kids, we are not on social media and never post pictures because to do so would put their lives in jeopardy. Not paranoid jeopardy but real-world issues, with real-world consequences," the "Gravity" actor wrote.

"We hope that you would agree that the need to sell advertisement isn't greater than the need to keep innocent children from being targeted."

The couple have twins, who were born in 2017.

Clooney has previously tangled with the Daily Mail, a British-based tabloid that has exported its aggressive celebrity journalism successfully to the United States in recent years with a populist online version.

Clooney accused the newspaper of fabricating an article saying his future mother-in-law objected to his upcoming marriage in 2014. 

The paper apologised, but while thanking them for the apology, Clooney said he did not accept it.

AFP has contacted the Daily Mail for a response to the letter.