Liberty University has launched an independent investigation into its former President Jerry Falwell Jr.

It follows his resignation last week amid lurid claims relating to an extramarital affair between his wife, Becki, and a hotel pool boy. Falwell denied knowing about the affair. 

When the scandal erupted, Falwell was already on indefinite leave from the university over a photo he posted to social media in which his pants were unzipped, showing part of his underwear. 

In a statement, the trustees said the past week had "challenged all of us to the core" .

"While we had been willing to extend grace and understanding to Jerry Falwell, Jr. before, once the revelations about his past personal life came more fully to light, we acted swiftly and decisively to ask for his immediate resignation, which we received," they said.

The trustees also addressed criticism that they were too slow to act on concerns about Falwell. 

"Some may say that all the signs were there for a long time before last week. It's certainly fair to say that there were questionable comments made, worrying behavior, and inappropriate social media posts, but all the signs were not there until the start of last week," they said.

"While we still didn't know the full scope of the matter, we have learned enough about the past to know that we had no choice but to take the leadership of Liberty University in a new direction.

"We are also committed to learning the consequences that have flowed from a lack of spiritual stewardship by our former president." 

The university is now conducting a "thorough investigation" into "all facets" of university operations under Falwell, including financial, real estate and legal matters.

While the search has already started for Falwell's replacement, the trustees said they were considering establishing a new role in the leadership of the university to "serve as a spiritual coach, mentor, and guide to help ensure that every member of the university leadership fulfills his or her spiritual responsibility to live out the Christian walk expected of each and every one of us at Liberty".