The American Israel Public Affairs Committee (AIPAC) is reportedly helping to fund advertisements attacking Senator Bernie Sanders in Nevada.

Pro-Israel lobby AIPAC is encouraging members to give to a Super PAC launching an anti-Sanders campaign which is run by the Democratic Majority for Israel (DMFI) group, two sources told The Intercept.

The DMFI, which was founded by longtime AIPAC strategist Mark Mellman, spent $800,000 on similar ads ahead of the Iowa caucus.

The ads will now appear in Nevada, which is set to have a caucus for the Democratic nomination on February 22.

Senator Bernie Sanders is seeking to challenge President Donald Trump in November's presidential election. Sanders won the New Hampshire's high stakes Democratic primary earlier this month, and will now move on to more difficult battlegrounds.

Perceived as the leftist frontrunner in the race for the Democratic nomination, the Jewish senator has been the most critical of Israel in the campaign.

According to The Intercept's sources, AIPAC is helping fund DMFI's anti-Sanders advertisements by "allowing donations to DMFI to count as contributions to AIPAC".

Donations of a hundred thousand dollars or more to AIPAC gives members special privileges, such as access to members of Congress at private conference.

This arrangement means donors give directly to DMFI, thereby not implicating AIPAC directly.

Spokesperson for DMFI Rachel Rosen told The Intercept she was unaware of any encouragement on the part of AIPAC. "As far as we know, what you are suggesting is completely untrue," she said.

"But because we are a separate organisation, we can't know exactly what other organisations are doing. Therefore, we are the wrong address for the the specific questions you ask — they need to [be] directed to AIPAC."

AIPAC denied the arrangement to The Intercept. "AIPAC is not and has not been involved in the ad campaigns of any political action committee," spokesperson Marshall Wittmann said.

Senator Sanders launched a scathing attack on the Israeli government at a Democratic debate in December, calling for a total overhaul of policy towards the country.

The presidential hopeful has previously vowed to end unconditional US support for Israel and promising to redirect some of the annual $3.8 billion in aid to humanitarian relief in Gaza.

"Israel has - and I say this as somebody who lived in Israel as a kid, proudly Jewish - Israel has the right not only to exist, but to exist in peace and security," Sanders said at the debate in Los Angeles in December.

"But what US foreign policy must be about is not just being pro-Israel. We must be pro-Palestinian as well," he added.

Sanders also lambasted Prime Minister Benjamin Netanyahu over his criminal indictment and racism against Palestinians, saying: "We must understand that right now in Israel we have leadership under Netanyahu, who has recently, as you know, been indicted for bribery, who, in my view, is a racist."

AIPAC was criticised this week for running ads on Facebook in late January which labelled certain congresswomen as "radicals in the Democratic Party" which are "pushing their anti-Semitic and anti-Israel policies down the throats of the American people".

The ads linked to a petition calling on supporters to "protect our Israeli allies especially as they face threats from Iran, Hamas, Hezbollah, ISIS and - maybe more sinister - right here in the US Congress".

AIPAC has retracted the ads and apologised for the campaign's wording, which it deemed to have "distorted our message".

Democratic Congresswoman Betty McCollum slammed the advertisement, in which she appearead alongside fellow Democrats congresswomen Ilhan Omar and Rashida Tlaib, as inciting "hate speech".

Since her election in 2001, McCollum has steadfastly advocated for Palestinian human rights in Congress. Ilhan Omar and Rashida Tlaib, who is Palestinian, have also advocated for the Palestinian cause and were barred from visiting Israel last year.

The Facebook campaign controversy comes as AIPAC prepares for its annual Policy Conference in early March.

AIPAC is one of the largest pro-Israel lobbies operating in Washington.

This article has been adapted from its original source.