York Regional Police's fraud unit is investigating the "internal theft" of customer data from 407 ETR, the company that oversees Highway 407, CBC News has learned.

On Wednesday, the former Progressive Conservative candidate in Brampton East, Simmer Sandhu, resigned over allegations of his involvement in the data breach. Sandhu called the allegations "totally baseless" and said he would work to clear his name.

His resignation came hours after 407 ETR announced it was informing some 60,000 customers that their names, mailing addresses and in some cases their phone numbers were stolen from the company's office in the past year.

Sandhu worked at the company for nine years, until he left about two months ago.

A spokesperson for York police said the investigation is in its earliest stages and few details were immediately available on Friday. The spokesperson did not say whether or not the investigation will include allegations of links between the data breach and Sandhu.

Liberal Leader Kathleen Wynne and NDP Leader Andrea Horwath both called for police to probe the circumstances of the stolen data while campaigning this week.

'We acted immediately,' Doug Ford says

On the campaign trail Friday, Ford told reporters that police had not contacted him nor his campaign team to discuss the stolen data.

He then reiterated the Tories parted ways with Sandu "as soon we found out about it."

Ford added that, to his knowledge, no other candidates or ridings have been linked in any way to the data breach.

"Again, as far as we know, that was the only riding. We acted immediately," he said.