In court documents, the university states Arthur Porter owes it more than $285,000.
In addition, McGill says Porter owes more than $30,000 dollars he was overpaid as part of his salary.
The court documents state McGill sent multiple letters to Porter demanding he reimburse the money he allegedly owes the institution.
The most recent letter was sent to the three addresses for Porter known to McGill and to Porter's attorney in Sierra Leone on Oct. 16.
The lawsuit includes an email Porter sent to the university on Oct. 23, saying he would try to pay back the loan with money from one of his family businesses in Sierra Leone.
The allegations against Porter have not been proven in court.
Porter resigned as executive director of the MUHC in December 2011, less than a month after he resigned as chair of the Security Intelligence Review Committee (SIRC)
CBC's calls and emails to Porter were not returned.