Daniel Dubois' team will hold an "internal inquest" after a video surfaced showing a reported "gathering" at his house just hours before his defeat to Oleksandr Usyk on Saturday.
Dubois, 27, did not arrive at Wembley Stadium until around 20:15 BST - less than two hours before his ring walk.
He was stopped in the fifth round, losing his IBF title as Ukraine's Usyk, 38, became a two-time undisputed heavyweight world champion.
The Londoner's trainer, Don Charles, said he could not confirm the accuracy of the video but admitted that it had taken place, with what he believed to be more than 30 people in attendance.
"I would like to change the word from party to gathering," Charles told BBC Sport.
He added an internal review into the events of fight night is expected, with promoter Frank Warren and his son George set to hold talks with Dubois' team.
"There's a meeting pending," Charles said. "We'll hold an internal inquest on what happened. Questions will be asked by Frank and George Warren."
Charles explained that a similar event had been held before Dubois' shock victory over Anthony Joshua in September, when he knocked out the former champion in the ninth round.
