Did Disputes Over 'Open Marriage' and Child Custody Lead to the Murder of a Wealthy Art Dealer?

Federal prosecutors allege the estranged husband of a millionaire art dealer conspired to have him killed in Brazil over a child custody dispute, after the couple’s partnership reportedly began to sour over his suggestion they pursue an open marriage.

Brent Sikkema, 75, a multi-millionaire art dealer from New York, was killed in his Rio de Janeiro home on Jan. 14, 2024. His estranged husband, 54-year-old Daniel Sikkema, has now been charged with conspiracy to commit murder-for-hire, the Department of Justice announced this week.

Daniel was initially charged by Brazilian authorities, who had requested an Interpol alert as he had left the country by then, per a wrongful death complaint filed against the defendant in New York state Supreme Court.

The charge came after Triana Prevez confessed to the murder, claiming he was hired to carry out the killing, local newspaper Folha de S.Paulo and O Globo reported last year; Folha reported Daniel was named as the mastermind in the case.

Now, U.S. authorities allege Daniel began plotting the killing as early as 2023, paying an assailant, identified by prosecutors only as "CC-1," $200,000 to commit the murder. He allegedly made the payments using a stolen identity.

Brent was stabbed 18 times in his face and chest, according to the wrongful death complaint reviewed by PEOPLE.

The couple’s marriage appears to have taken a downturn a few years before the murder. The executor of Brent’s estate claimed in 2019 Daniel proposed the idea of an “open marriage,” which Brent did not want, per the complaint.

This caused their marriage to “deteriorate,” per the complaint, and in 2022, Daniel filed for divorce.

Things only went further downhill from there.

In the complaint, Brent's executor accuses Daniel of trying to steal $200,000 from his widow's bank account, and later disappearing for weeks with the couple's child and a suitcase full of cash; he allegedly claimed they were moving to Cuba, before eventually resurfacing in New York because they needed money.

The executor even accused Daniel of framing Brent for a bogus plot to commit mass murder at John F. Kennedy International Airport in New York; Brent was detained by police in a holding cell for nearly 24 hours until being released due to lack of evidence.

Daniel's lawyer Nicholas Kaizer denied the accusations to PEOPLE.

Related: Prominent New York Art Dealer Allegedly Stabbed to Death in Brazil: Report

Want to keep up with the latest crime coverage? Sign up for PEOPLE's free True Crime newsletter for breaking crime news, ongoing trial coverage and details of intriguing unsolved cases.

Daniel would later demand full custody of the child and $6,000,000 from his millionaire ex, but Brent rejected both demands, per the complaint.

Daniel has been charged with one count of conspiracy to commit a murder-for-hire, one count of murder-for-hire, one count of conspiracy to murder a person in a foreign county and one count of passport fraud, per the DoJ statement.

Daniel has pleaded not guilty to the charges, Kaizer tells PEOPLE.

If you are experiencing domestic violence, call the National Domestic Violence Hotline at 1-800-799-7233, or go to thehotline.org. All calls are toll-free and confidential. The hotline is available 24/7 in more than 170 languages.

Read the original article on People