A Russian oligarch with close ties to President Vladimir Putin partially funded the lavish post-wedding celebrations for Donald Trump Jr. and his new wife Bettina Anderson, according to a ProPublica investigation released Monday and confirmed by the couple.

The report detailed that Umar Kremlev, head of the International Boxing Association, paid hundreds of thousands of dollars in expenses for the May event held across two private islands in the Bahamas. Costs included renting one island at roughly $100,000 per night for receptions and guest accommodations, as well as a fireworks display estimated at $70,000.

Trump Jr. married Anderson in a private ceremony on May 22 with only family present before the larger three-day celebration that followed. Kremlev attended the festivities along with a group of Russian-speaking guests, which surprised some other attendees among the roughly 50 total guests.

In an Instagram statement posted Monday and signed by both Trump Jr. and Anderson, the couple described Kremlev as a "dear friend" who "very generously hosted two incredible nights of celebrations for us AFTER our wedding." They called the contribution "an extraordinarily generous wedding gift from a friend" for which they remain grateful.

Kremlev met Trump Jr. through shared interests in hunting and boxing, according to a spokesperson for the president's son. The two do not have a business relationship, the spokesperson added. Kremlev's office described the relationship as friendly and said political matters have never been discussed.

Kremlev has longstanding connections to the Russian government. He received the Order of Friendship from Putin earlier this year and accompanied the Russian leader on a trip to China days before the wedding events. The International Boxing Association has received funding from Russia's state-owned Gazprom energy company.

The payments for the wedding-related expenses reportedly came through a Dubai-based entity affiliated with the boxing association. President Donald Trump did not attend the wedding.

The revelation has prompted questions and concerns about potential foreign influence, especially on close family members that have the ear of the president. Trump Jr. remains a private citizen and acceptance of gifts from foreign nationals is not illegal.