On a busy street near the Dutch Parliament, three white musicians in blackface regale passersby with holiday tunes about the Dutch Santa Claus, Sinterklaas, and his slave, Black Pete.

Many native Dutchmen view dressing up as Black Pete in December as a venerable tradition, but others consider it a racist affront to victims of slavery. With Holland marking the 150th anniversary of abolition this year, the controversy over Black Pete has reached new heights. Hundreds demonstrated against the custom in Amsterdam last month, and more than 2 million signed a petition supporting it.

Through it all, Dutch Jews — some of whom celebrate their own version of the Black Pete custom, called “Hanukklaas” — have largely remained silent.

But that changed in October, when Lody van de Kamp, an unconventional Orthodox rabbi, wrote a scathing critique about it on Republiek Allochtonie, a Dutch news-and-opinion website. “The portrayal of ‘Peter the slave’ dates back to a period when we as citizens did not meet the social criteria that bind us today,” Van de Kamp wrote.

Speaking out against Black Pete is part of what van de Kamp calls his social mission, an effort that extends to reminding Dutch Jews of their ancestors’ deep involvement in the slave trade. In April, he is set to publish a book about Dutch Jewish complicity in the slave trade, an effort he hopes will sensitize Jews to slavery in general and to the Black Pete issue in particular.

“I wrote the book and I got involved in the Black Pete debate because of what I learned from my Dutch predecessors on what it means to be a rabbi — namely, to speak about social issues, not only give instructions on how to cook on Shabbat,” van de Kamp told JTA.

“Money was earned by Jewish communities in South America, partly through slavery, and went to Holland, where Jewish bankers handled it,” he said. “Non-Jews were also complicit, but so were we. I feel partly complicit.”

Though he holds no official position in the Dutch Jewish community, van de Kamp, 65, is among the best-known Orthodox rabbis in the Netherlands, a status earned through his several books on Dutch Jewry and frequent media appearances.

His forthcoming book, a historical novel entitled “The Jewish Slave,” follows an 18th-century Jewish merchant and his black slave as they investigate Dutch-owned plantations north of Brazil in the hope of persuading Jews to divest from the slave trade. In researching the book, van de Kamp discovered data that shocked him.

In one area of what used to be Dutch Guyana, 40 Jewish-owned plantations were home to a total population of at least 5,000 slaves, he says. Known as the Jodensavanne, or Jewish Savannah, the area had a Jewish community of several hundred before its destruction in a slave uprising in 1832. Nearly all of them immigrated to Holland, bringing their accumulated wealth with them.

Some of that wealth was on display last year in the cellar of Amsterdam’s Portuguese Synagogue, part of an exhibition celebrating the riches of the synagogue’s immigrant founders. Van de Kamp says the exhibition sparked his interest in the Dutch Jewish role in slavery, which was robust.

On the Caribbean island of Curacao, Dutch Jews may have accounted for the resale of at least 15,000 slaves landed by Dutch transatlantic traders, according to Seymour Drescher, a historian at the University of Pittsburgh. At one point, Jews controlled about 17 percent of the Caribbean trade in Dutch colonies, Drescher said.

Jews were so influential in those colonies that slave auctions scheduled to take place on Jewish holidays often were postponed, according to Marc Lee Raphael, a professor of Judaic studies at the College of William & Mary.

In the United States, the Jewish role in the slave trade has been a matter of scholarly debate for nearly two decades, prompted in part by efforts to refute the Nation of Islam’s claim that Jews dominated the Atlantic slave trade. But in Holland, the issue of Jewish complicity is rarely discussed.

“This is because we in the Netherlands only profited from slavery but have not seen it in our own eyes,” van de Kamp said. “The American experience is different.”

The slavery issue is not van de Kamp’s first foray into controversial territory. In Jewish circles, he has a reputation as a contrarian with a penchant for voicing anti-establishment views.

That image was reinforced last year when he spoke out against a compromise the Dutch Jewish community had reached with the government over kosher slaughter. Designed to avert a total ban, the compromise placed some restrictions on kosher slaughter that Holland’s chief rabbis said did not violate Jewish law. Van de Kamp denounced the deal as an unacceptable infringement on religious freedom.

More recently, he angered Dutch activists by suggesting that vilifying Dutch Muslims helped generate anti-Semitism. He also advocated dialogue with professed Muslim anti-Semites at a time when Jewish groups were calling for their prosecution.

But his reputation as a maverick rabbi in a consensus–oriented community has also endeared van de Kamp to some supporters.

“He is in a league of his own,” says Bart Wallet, an Amsterdam University historian and expert on Jewish history. “From the sideline, he is free to criticize and does not have to conform to anything.”