OPP said a court order has been issued to obtain recordings of conversations between independent candidate Andrew Olivier and members of the Liberal Party.
Premier Kathleen Wynne asked Andrew Olivier, the Liberal candidate in Sudbury in last June's general election, not to seek the nomination for Thursday's byelection because she had another candidate she wanted to appoint.
Olivier has alleged that the Liberals offered him a job or appointment in exchange for him stepping aside for Glenn Thibeault, who left his job as an NDP MP to run for the provincial Liberals.
Olivier, who is quadriplegic and records conversations in lieu of taking notes, posted audio to YouTube of his talks with two Liberals, including Ontario Liberal campaign director Pat Sorbara.
OPP Det.-Supt. Dave Truax said police spoke to Olivier during the initial investigation.
"Olivier provided a lengthy statement to police which revealed no evidence to support the belief that a criminal offence had occurred," he said.
"Olivier had the opportunity to voluntarily offer the recordings he had made at the time to the OPP. Mr. Olivier chose not to do so, but then released recordings with two individuals via social media."
Elections Ontario is also looking into Olivier's allegations, after the New Democrats suggested the Liberals' alleged conduct violates the Election Act, which makes it an offence to promise a job or appointment to induce a person to withdraw their candidacy.