GURGAON, India — Prospective buyers of luxury apartments in the new Trump Towers project outside India's capital are being lured with an unusual promise: If you buy a flat, we will fly you to the United States to meet Donald Trump Jr.

The developers of the 600-foot high-rises unveiled a sleek sales office in the New Delhi suburb of Gurgaon last week, claiming they racked up $23 million in sales — more than 20 units — in the first day.

The sweetener?

One of the developers, Pankaj Bansal, told the Press Trust of India that "Donald Trump Jr. will host" the first 100 buyers in the United States.

Bansal, the director of M3M India, one of the partners on the project, declined to comment for this story. But a representative for the project confirmed Bansal's remarks and added that the specifics of the buyers' trip — where they would be flown and under what circumstances they would meet Trump Jr. — were still being worked out.

Trump Jr. and the Trump Organization in New York did not respond to emails or telephone calls requesting specifics on their Indian partners' plan.

The launch of the new towers comes amid rising concerns that President Trump's children — including Trump Jr. and Eric Trump, who are running their father's business while he serves as president — are using their names to profit from their father's presidency, and that foreign officials and others may stay in Trump hotels or buy Trump properties in attempts to curry favor or gain special access to the first family.

A study released last week by the watchdog group Citizens for Responsibility and Ethics in Washington (CREW) found that the price of the popular "Ivanka Suite" in the Trump International Hotel in Washington, for example, increased from $914 a night last year to $2,134 a night in 2018.

The Washington Post’s David A. Fahrenthold takes a look at the Trump Organization’s real estate business since President Trump took office. (Bastien Inzaurralde/The Washington Post)

Norman L. Eisen, the co-chairman of CREW and a former Obama ethics adviser, called the Indian developers' offer "outrageous."

"They are auctioning off access to the first family in a foreign land. What is to stop a foreign national with interests before the U.S. government from purchasing a flat, or tagging along with someone who did, simply to ask Don Junior to raise some issue or concern with his father?" Eisen said.

The Trump Organization has more business entities in India than any other foreign country, financial filings show, with licensing bringing in estimated payments of between $1.6 million and $11 million since 2014.

As with most of its overseas deals, the Trump family has lent its name, technical assistance and advice but has not invested directly in any of its five projects here.

Along with the Trump Towers Delhi NCR (National Capital Region) in Gurgaon, construction on which is expected to begin in three to four months and finish in 2023, the projects include two residential towers in the low-key city of Pune, a tower with a glittering gold facade in Mumbai, a planned office tower in Gurgaon and another residential project in the eastern city of Kolkata.

Some of the Trump partners have been the subject of tax or money-laundering investigations, and at least three have connections to prominent Indian politicians, a scenario that the Center for American Progress called in a report "a breathtaking array of conflicts."

M3M, for example, was embroiled in a long-running tax investigation that the company said was resolved in its favor. Kalpesh Mehta, the head of Tribeca Developers, the co-partner on the Gurgaon project, was one of three Indian developers who visited Donald Trump shortly after his election in November whose pictures with the president-elect set off a firestorm on social media.

The luxury real estate market in India is sluggish at the moment, but the Trump Organization says that sales of its more moderately priced units in Kolkata have done well — with the building more than 65 percent sold after a "soft launch" last year.

Last week, employees from Mumbai-based Tribeca Developers gathered outside the new Trump sales office in the Oberoi, Gurgaon — a luxury hotel in a suburb that is home to multinational corporations and small farming villages where cattle still meander along dusty lanes. (The area recently changed its name from Gurgaon to Gurugram.)

They did not allow a reporter to speak to any prospective buyers, who were ushered in one by one to see a model of the two towers emblazoned with the Trump name. The apartment homes in the project — with private elevators and access to a nine-hole golf course — range in price from about $780,000 to $1.6 million.

A man in business attire who was on hand to see a sales presentation asked a sales representative what the "discounts" were.

She laughed and said that sales have been so good that "we're not even thinking about discounts at this point."