A CBC investigation first brought this story to light in 2013 when the fundraiser was held at a Woodbridge banquet hall. The city's lobbyist registrar investigated a number of lobbyists who attended, and found that the four in question donated more than $23,000 total.
Linda Gehrke's report said there was no evidence that the money actually influenced Mammoliti, but that the donations were against lobbying bylaws and "improper."
Those lobbyists will have to attend training about city rules.
They've also been told not to lobby Coun. Mammoliti.
One of them is developer Louie Santaguida, whose condominium projects Mammoliti has supported in council.
Another is prominent lawyer Ralph Lean, who has been a political fundraiser for former mayor Rob Ford.
Developers Sheldon Libfeld, who contributed to the fundraiser on behalf of Oakdale Village Homes, and Medallion Developments are also named by the city.
Last year, the Integrity Commissioner found Coun. Mammoliti had violated the councillors' code of conduct by accepting money in relation to the fundraiser.