The confidential 30-page document, received by The TES, was prepared by a team from the Further Education Funding Council for its chief executive David Melville. Mr Chapman was suspended by governors last March after complaints from more than 50 staff. His resignation was announced on February 12.
The investigation, involving 38 interviews, was carried out after allegations from whistleblowers.
The report said investigators "substantiated" a number of allegations about the principal's management style. These include claims that:
* "The principal's reign was characterised by bullying and intimidation and a mismanagement of initiatives and procedures;"
* "Staff were subject to disciplinary procedures for allegedly failing to submit tutorial records for audit purposes and failing to follow instructions from a senior manager;"
* "A number of staff are without contracts or correct pay after considerable time in post."
Investigators said the college had failed to comply with its own anti-bullying policy, which involved complaints being invetigated by a "trained and competent person".
"Neither management nor staff have been provided with the requisite training," the report said, although these issues were being addressed by the college since Mr Chapman's departure.
The investigators also found that a member of staff was asked to exaggerate the number of students attending induction sessions, and that the number of telephone helplines at the college had also been exaggerated.
The report said: "Nine lines open for 45 hours per week over a year, divided by 5,000 students, would mean a theoretical availability of four hours per student. In fact, the college only had two lines for this purpose."
Responding to allegations of poor management and staff support, the report upheld a complaint over redundancy notices being wrongly issued to some staff in engineering, as a result of an timetabling error. Staff were left feeling unsupported and vulnerable, the report said.
A number of complaints were not substantiated. These included claims that inaccurate achievement figures were provided to the FEFC, that timetables were badly-organised and that governors refused to discuss problems with union representatives.