During his mayoral term, he was offered an option on 10,000 shares of stock in Northern Ontario Natural Gas, a company run by Ralph K. Farris that was seeking a municipal agreement on the construction of a natural gas pipeline through Northern Ontario.
After a second investigation, Landreville was charged with municipal corruption and conspiracy, and was acquitted as there was no evidence that he had exerted any influence on Sudbury's city council to approve the NONG contract.
In response, however, the Law Society of Upper Canada held a secret hearing in which it determined that despite the acquittal, Landreville's conduct had fallen below the "standards of probity" demanded of a judge, and called for his resignation.
In 1966, Prime Minister Lester Pearson appointed a Royal Commission, chaired by Ivan Rand, to investigate the case.
Controversially, the Law Society report was admitted into the proceedings, but the original judgement acquitting Landreville of misconduct was not.