Adultery website Ashley Madison is offering a 500,000 Canadian dollar reward for information on hackers who published its customers' details.
The website, which markets itself as facilitating extra-marital affairs, was targeted by a hacker group known as The Impact Team who breached Ashley Madison's servers last month and threatened to expose its clients if the site was not shut down.
When the site's Toronto-based parent company Avid Life Media refused, the entire Ashley Madison client list, which claims to have more than 30 million users worldwide including in the UK, was published online, triggering extortion attempts and two unconfirmed reports of suicides, Canadian police said.
The information was published on the Dark Web - a sub-level of the internet that cannot be accessed through normal browsers - but other groups have since posted sections of the alleged list, including names and postcodes, online.
Canadian police in Toronto said the parent company of the website, Avid Life Media, is offering the reward following "enormous social and economic fallout".
"This hack is one of the largest data breaches in the world," said Toronto police acting superintendent Bryce Evans. "This is affecting all of us. The social impact behind this leak, we're talking about families, we're talking about children, we're talking about wives, their male partners."
Evans confirmed the force is investigating cases of criminals attempting to extort Ashley Madison clients by threatening to expose them, as well as hate crimes. He gave no further information on the two unconfirmed reports of suicide.
Avid Life Media was sued in Canada last week in a class-action suit by two Canadian solicitors' firms who said they were seeking 760 million Canadian dollars in damages for users of the site.