The agency said it has concluded there wasn't enough evidence to support charges under the federal Immigration and Refugee Protection Act after an investigator's report was completed last November.
Last September, the federal Immigration Department referred allegations that the immigration program was marred by bribery to the agency and the RCMP.
The agency said it now considers the matter closed.
The RCMP said Tuesday it is still conducting its investigation and expects to submit a report in a few weeks.
The accusations surfaced after a former employee of the program alleged that senior provincial officials were bribed in order to expedite immigration applications.
The provincial nominee program allowed foreign investors to fast-track receipt of Canadian visas by providing about $150,000, some of which was invested in P.E.I. companies.
The program was shut down four years ago after the federal government said the program was operating outside rules that required immigrants to be actively involved in companies they invested in.
In recent days, some Chinese citizens who took part in the program have expressed their anger after waiting more than two years for refunds after the province accepted their money but Ottawa denied them visas.
A spokeswoman for the provincial government said in an email Tuesday that there are seven trust funds that may eventually provide refunds of $55,000 for each rejected applicant.
Rebecca Bruce said each fund was established by government-appointed intermediary firms who matched up immigrant investors with P.E.I. companies.
Jamie Aiken, the province's director of immigration, has said the money totals about $9 million — enough to refund 164 rejected applicants. But he also said it can only be released when each trust fund has enough money to cover all of the rejected applicants.
Nancy Caron, a spokeswoman for the federal Immigration Department, said Ottawa has rejected 52 provincial nominees so far and has another 100 applications it is still reviewing.
The federal government said it warned Prince Edward Island's government four years ago there would be delays in processing 2,200 applicants whose cash the province accepted in 2008.