He did not immediately return a call seeking comment. University spokesman Scott Lamb said he had no further comment.
In an interview this week with Lynchburg radio station WLNI, Falwell said the woman in the photo was his wife's assistant and the picture was taken during a "costume party" while on vacation.
"Lots of good friends visited us on the yacht," the caption of the photo said, in part. "I promise that's just black water in my glass. It was a prop only."
He said the woman — who also had her midriff exposed — was pregnant, couldn't get her pants zipped and he imitated her, saying it was all in "good fun."
"I've apologised to everybody, and I've promised my kids ... I'm going to try to be a good boy from here on out," he told the interviewer.
On Thursday, Republican US Representative Mark Walker, of North Carolina, a pastor who previously taught at Liberty, called Falwell's behavior "appalling" and said he should resign.
Besides Walker, some pastors who graduated from Liberty spoke out this week calling for a change in leadership at the school. Mark Davis, a Texas-based pastor, tweeted that "the name of Christ and the reputation of Liberty will continue to be dishonoured" without action against Falwell by the board. Colby Garman, a pastor who has served on the executive board of the Southern Baptist Convention of Virginia, tweeted on Monday it was "bewildering" to see Falwell maintain the board's support. He responded to Friday's news with appreciation.
"How is this Jerry Falwell Jr. photo even real?" tweeted conservative TV personality Meghan McCain, daughter of the late U.S. Sen. John McCain. "Also if you're running the largest Christian university in America maybe don't put photos of yourself on social media with your pants undone on a yacht — with random women in bad wigs. So gross, so hypocritical."
The late Falwell founded Liberty in 1971 with just 154 students. Under the leadership of Falwell Jr, who is an attorney and not a minister, Liberty has grown into a leading evangelical university, with an immaculate campus and a significant endowment. Students must follow a strict code of conduct that includes modest dress and a ban on alcohol consumption.
In recent years, Liberty has served as a regular speaking spot for ambitious Republicans courting the young evangelical vote. US Senator Ted Cruz kicked off a presidential campaign there in 2015.
Falwell was among the earliest Christian conservatives to endorse Trump's previous election campaign. In late 2016 he told The Associated Press Trump had offered him the job of education secretary but he turned it down for personal reasons.
The vacation photo was the most recent in a string of controversies dogging Falwell in recent years, in both his role at Liberty and his personal life.
Last year, he settled a federal lawsuit in Florida over a real estate venture that involved a young Miami pool attendant, a case that drew national attention.
He more recently sparred with Virginia Governor Ralph Northam and local officials in Lynchburg over his handling of coronavirus restrictions. He also faced stinging criticism from a group of Black alumni who said in a letter he should step down after he mocked Virginia's mask-wearing requirement in a tweet by invoking a blackface scandal that engulfed Northam last year. Several Black Liberty staff members resigned following the tweet, and several high-profile Black student-athletes announced transfer plans.
On Friday, Pastors Chris Williamson, Eric Carroll, and Maina Mwaura, who organised the June letter, issued a statement applauding the board's decision.
"Liberty University deeply impacted us as students and we hope that its leadership can return to a focus of training 'young champions for Christ' with Biblical conviction for the Gospel and justice," the statement said.
