Less than two months after the launch of the new Presto mobile app, a Toronto man is urging Metrolinx to correct an apparent glitch that he claims can shut down fare gates and card loading machines at subway stations.

Robert Leyzerovich, who works in software quality assurance and tests mobile apps professionally, said he discovered the issue while playing around with the app's new function that loads money on a Presto card.

Leyzerovich says he's sounding the alarm because he's worried the glitch will lead to more fare evasion, just weeks after the City of Toronto's auditor general found the TTC lost $61 million dollars in 2018 due to passengers avoiding paying fares.

You can watch Leyzerovich demonstrate what's happening with his Presto card in the video below:

"If the wrong person figures this out — how it's done — a lot more can happen," Leyzerovich told CBC Toronto.

"I knew there was going to be glitches, but nothing this serious," he added.

He claims he encountered a series of errors while testing the loading function on the app. When he later went to tap his card at a subway station, he said the screens on the gates turned black, and that the same thing happened when he took his card to a fare loading machine.

"They had to completely restart the system," said Leyzerovich, who claims he reported the problem to both the TTC and Presto immediately after.

Metrolinx said it is investigating Leyzerovich's claim.

'It turned black'

Metrolinx unveiled the Presto app in late January, after a month of testing by more than 15,000 users. It has a number of features, including the ability to load funds, manage multiple cards and issue notifications for a low balance.

Leyzerovich said he first installed the app a month ago on his Samsung smartphone.

PRESTO! We have an app for that.<br>The PRESTO App is officially out of beta testing and available to everyone on Android or iOS. A special thanks to all of our App testers.<br>Download it here: <a href="https://t.co/NvXlt3YPHc">https://t.co/NvXlt3YPHc</a> <a href="https://t.co/wysuRxVU7Z">pic.twitter.com/wysuRxVU7Z</a> —@PRESTOcard

"I was curious about the functionality of exactly how it worked," said Leyzerovich.

After trying out different loading functions on the card, Leyzerovich said he tried to put $50 on the card using the app but it didn't work.

"I closed the application, and it still showed a 'please put your card toward the phone' to load the balance. But once I did that, the app crashed," said Leyzerovich.

He said he tried again but no balance was ever loaded. When he got to Islington subway station, he said he was curious to see what would happen if he tapped his card, and that's when things went wrong.

"When I tapped it at the access point of where you actually walk into the subway it turned black — the entire screen."

Leyzerovich said he went to tap at other gates and the same thing happened. He said he spoke to a TTC official at the station who told him to try the loading machines.

Leyzerovich claims the glitch turned the screen on the fare gate black and locked the doors shut. He claims the same thing happened at the fare loading machine. (John Lesavage/CBC)

"When I placed it in there that device completely shut down and could not be turned back on," said Leyzerovich, who said that in the meantime, no one could tap their cards and operators were forced to let the passengers in for free.

The TTC estimates it lost $3.4 million in 2018 because of malfunctioning Metrolinx equipment.

Metrolinx, TTC respond

In an emailed statement, Metrolinx confirmed it's investigating the claim and that it's been in touch with Leyzerovich.

"The security of the Presto system is central to our work," the statement reads.

"While we can't comment on the specifics of the investigation, any individual who deliberately tries to shut down or tamper with a Presto device could be subject to prosecution."

In an e-mail, a spokesperson for the TTC said: "We take issues like this seriously and we will continue to look into this occurrence."

Meanwhile, Leyzerovich said he worries about others who might be able to figure out the glitch.

"There's so many transactions that are done. It's bound to happen sooner or later," he said.