A Progressive Conservative candidate abruptly quit on Wednesday evening, hours after his former employer announced it was investigating an internal data breach that affected 60,000 customers.

Simmer Sandhu announced on Twitter that he was stepping down as the PC candidate in Brampton East because of allegations "pertaining to both my work life and my nomination campaign."

Sandhu worked nine years at 407 ETR, the company that owns and operates the 407 toll highway through the GTA.

Late Wednesday afternoon, 407 ETR announced it was informing 60,000 customers that their names, mailing addresses, and in some cases their phone numbers were stolen from the company's office during the past year.

"The incident is being investigated as an inside theft of data," said the company in a statement. It said local police and the province's information and privacy commissioner have been informed.

A company official would not say who was being investigated but confirmed that Sandhu worked for 407 ETR until about two months ago.

<a href="https://twitter.com/407_ETR?ref_src=twsrc%5Etfw">@407_ETR</a> to advise affected customers of internal theft of customer data, limited to account name addresses/phone number. No financial, credit card, payment, account or other information impacted - No indication of an external breach of systems - Read <a href="https://t.co/bOfdLanm9m">https://t.co/bOfdLanm9m</a> —@407_ETR

"These allegations are totally baseless. I absolutely deny them," Sandhu said on Twitter. He said he will vigorously defend himself, but added, "I feel it is impossible for me to continue as the PC candidate in Brampton East while doing so."

"In light of the investigation into Simmer Sandhu, he felt it was necessary to stand down as a candidate and we accepted his resignation," said PC spokesperson Melissa Lantsman in a statement.

Liberal campaign co-chair Deb Matthews described the allegations as "very disturbing" in a written statement released Wednesday evening.

"If these allegations are true, it goes much deeper than one candidate. It means that the Conservative party may be in possession of stolen personal information that they could be using for political advantage," Matthews wrote.

The PC party named Sudeep Verma as its candidate to replace Sandhu.