The suspension came Thursday night and is effective immediately.
Nigerian Boston Celtics Coach Ime Udoka has been suspended for the 2022-23 season.
According to ESPN, the suspension came Thursday night and is effective immediately.
A decision about Udoka's future with the organisation will be made later, the team said.
The team also cited violations of team policies in its announcement.
SaharaReporters earlier reported that 44-year-old Udoka had an intimate relationship with a female member of the franchise’s staff.
Udoka has also apologised to fans, family and the Celtics organisation for letting them down.
"I want to apologise to our players, fans, the entire Celtics organisation, and my family for letting them down," Udoka said in a statement to ESPN's Malika Andrews.
"I am sorry for putting the team in this difficult situation, and I accept the team's decision. Out of respect for everyone involved, I will have no further comment."
The season-long suspension is largely unprecedented for a sitting head coach in the NBA.
The Celtics have made assistant coach Joe Mazzulla the interim head coach, sources told Wojnarowski.
Udoka joined the Celtics last summer after spending time with the San Antonio Spurs, Philadelphia 76ers and Brooklyn Nets as an assistant coach following his NBA playing career.