Glasgow Kelvin College has asked its auditors to review the payments - made to former members of staff at North Glasgow College - after a request from the Scottish Parliament's audit committee.
Ronnie Knox, the former principal of North Glasgow College, and John Gray, his vice-principal, received £471,000 between them under the deal, which followed the college's merger with two other institutions to form the new Glasgow Kelvin College.
Mr Knox, who received a salary of about £120,000, was given a payout of more than £310,000, while Mr Gray, who earned £80,000, received more than £160,000.
Caroline Gardner, Auditor General for Scotland, has stressed there is no evidence the payments were wrongly calculated, or they were illegal or fraudulent. But a report by Audit Scotland raised the matter of transparency over the way they were sanctioned, stating there was no evidence they were subjected to "appropriate approval" or assessed as providing value for money.
A spokeswoman for Glasgow Kelvin said: "The audit committee has requested the college commission a further review of the matter and auditors have been engaged to undertake this task. The resultant report will be available to the committee in due course.
"We take this opportunity to reassure our students, staff, stakeholders and communities that the matter does not relate to Glasgow Kelvin College, which remains committed to the highest standards of governance, transparency, social responsibility and accountability in its use of public monies."
Last night, the size of the payments, approved by the board of the former college and its remuneration committee, sparked anger among politicians.
Hugh Henry, a Labour MSP and convener of Holyrood's audit committee, said: "It is a significant sum from college budgets, which have been exceptionally hard-pressed. Courses have been cut, there are reduced student numbers and staff have been struggling to cope. These are huge costs, associated with a process many in the college sector thought pointless."
Scottish Liberal Democrat MSP Tavish Scott said: "Students will wonder why their college is spending half-a-million pounds on severance for two members of staff. They deserve assurances this use of valuable college resource is the best deal for all affected."
Scottish Conservative education spokeswoman Mary Scanlon said: "There is no clear audit trail to explain this sizeable severance package and that is completely unacceptable. It is vital in these situations that there is absolute transparency."
A report on the issue for Audit Scotland also raised the matter of both members of staff being allowed to go on "gardening leave". It said: "According to the minutes of the remuneration committee, the committee agreed the vice-principal should be offered six months' garden leave on full pay. No details are provided in the minutes of the basis for this decision, including whether it represented value for money.
"I understand the principal was not required to work his notice period beyond October 31. In this case there does not appear to be any minuted decision."
Mr Knox said the way the payments were sanctioned and the amount agreed had been dealt with by the college's remuneration committee under due legal process and he was not privy to any of their discussions. Mr Gray could not be contacted for comment.
The use of severance payments in the merger process was seen as an essential short-term measure as overall numbers of executive staff were cut, with savings expected in the long-term.