Well-known New York art dealer Brent Sikkema has died in Brazil, his gallery Sikkema Jenkins & Co confirmed by phone to Artnet. Early reports from Rio de Janeiro have indicated he was murdered.

Sikkema, 75, was found dead at an apartment he owned on Rua José Abreu Fialho in the affluent neighborhood of Jardim Botânico, the Civil Police confirmed in an email to Artnet.

“The Capital’s Homicide Department (DHC) was called in and is investigating the death of Brent Sikkema, 75. Forensics were carried out on the property where the victim’s body was found. Officers will listen to witnesses, are looking for more information and are carrying out other investigations to shed light on the case,” police said.

Police also said he had been stabbed with a sharp object, the Rio-based newspaper O Globo reported.

Sikkema’s lawyer Simone Nunes told O Globo that she had been unable to reach him since Saturday ahead of a work meeting planned for Monday. The lawyer, who had a key to his home, went to check on him and found him dead on a bed. While the house had security cameras inside, it is so far unclear whether they will provide any evidence.

Nunes told O Globo that Sikkema had been in Brazil for Christmas, According to her, he had applied for a visa to move to the country, though he was due to return to New York on Tuesday.

“We can confirm the death of a U.S. citizen in Rio de Janeiro,” the U.S. State Department said in an email to Artnet. “We offer our sincerest condolences to the family. We are providing all appropriate assistance to the family. Due to privacy considerations, we have no further comment.”

O Globo reported that Nunes will work with the U.S. State Department to have his body sent home to New York.

Sikkema was born in 1948, raised in Morrison, Illinois, and graduated from the San Francisco Art Institute. He began his gallery work in 1971 as director of exhibitions at the Visual Studies Workshop in Rochester, New York.

He went on to serve as Vision Gallery in Boston, first as director from 1976 until 1980, then as owner from 1980 to 1989. After moving to New York in 1991, he opened a contemporary art gallery in the SoHo neighborhood of Manhattan named Wooster Gardens. It moved Chelsea in 1999 and was later renamed to Sikkema Jenkins & Co. It was known for showing artists including Jeffrey Gibson, Vik Muniz, and Kara Walker.

After initial news of his death broke, Sikkema Jenkins & Co put out a brief statement about his passing. “The gallery grieves this tremendous loss and will continue on in his spirit,” the statement reads.