Côté released his first annual report as commissioner on Tuesday.
In it, he argues his office lacks investigative tools and that he needs the power to apply to a judge for an order to force witnesses to talk.
"It regularly happens, in the course of our investigations, that we approach individuals who we know will have information relevant to a file we are working on, only to be told that they do not wish to talk to us — they refuse to say anything," Côté wrote in his report.
- Read the commisioner's report (pdf)
The commissioner also says that out of the more than 400 different offences under the Canada Elections Act, many are regulatory in nature, yet the only way to impose sanctions is to launch a full prosecution.
"To prosecute a case is an expensive and lengthy proposition," the report said. "For that reason, prosecutions are reserved for the most serious breaches and are ill-suited for the majority of situations."
Since the robocalls scandal broke in the news, Elections Canada has been under increased scrutiny over its investigations and the results of those investigations.
There has been one charge filed in April in relation to the robocalls case, when automated phone calls misdirected voters to the wrong polling stations in Guelph, Ont.
As well, just last Thursday, Elections Canada announced charges against Conservative MP Dean Del Mastro for overspending in the 2008 election and for allegedly trying to cover it up.
And earlier this year, three Conservative MPs got in a protracted fight with Elections Canada over their 2011 election expenses, after the election agency tried to force them to correct their spending files, using the threat of barring them from the House until they made the changes.
Thursday's report highlights other challenges facing the commissioner, including the task of balancing the need to be transparent about what the office is doing and the need to protect the confidentiality of investigations. Investigations are also becoming more complex, both legally and technologically.
Pierre Poilievre, minister of state for democratic reform, said the government had received the commissioner's report and "will carefully consider the issues raised."