The sperm of a Brooklyn mathematics professor who has fathered at least 33 children in the last decade has been banned for use in Israel.

The New York Post reported on Sunday, Father’s Day in the United States, that an Israeli woman flew Ari Nagel, 42, to Israel in order to have him donate and freeze his sperm at a private clinic. Nagel told the Post that an employee immediately disposed of his sample and told him that the facility, and all sperm banks in Israel, had been notified that Nagel’s sperm cannot be used in Israel.

Sperm donation in Israel is anonymous, unless the male donor signs documents saying he will co-parent with the mother. But Nagel already has signed such a document with six other women in Israel, who have not been allowed to use his sperm, which remain frozen in a storage facility, according to the Post.

Get The Jewish News Daily Edition by email and never miss our top stories Free Sign Up

Israel’s Ministry of Health said in a letter to the latest would-be mothers that: “considering the number of women whom Mr. Nagel impregnated with his sperm . . . it is our position that the claim of an intention to perform true joint parenthood with Mr. Nagel is not sincere or reasonable.” The woman has taken the case to Israel’s Supreme Court.

Seven new babies sired by Nagel have been born in the United States since last Fathers’ Day, according to the newspaper.

Nagel is married and has three children ages 4, 7, and 14.

He told the Post that he has received requests from women around the world, and that he has a lot of clients in England. He does not charge for his sperm, and has been successfully sued for child support five times even though the women he gives his sperm to all promise in advance that they won’t sue.

Nagel told the Post two years ago that he typically produces the sperm in a men’s restroom and gives it to the woman in a cup. She then inserts it in the women’s restroom. Many of the women are more comfortable meeting Nagel in a public place than in his apartment near downtown Brooklyn, the newspaper reported at the time. He also told the newspaper that his relationship with his wife has not been romantic in years and that they sleep in separate bedrooms.