The pressure may be mounting on Equifax.

Federal prosecutors on Thursday charged a second Equifax executive with insider trading — part of an ongoing probe into the massive data breach at the credit reporting agency.

The probe follows reports that some Equifax executives sold some shares after the company learned of the breach — but before it was disclosed to the public.

The probe is focusing on sales of stock made by former Chief Financial Officer John Gamble, president of US information solutions Joseph Loughran, and president of workforce solutions Rodolfo Ploder, according to reports.

An internal Equifax probe cleared the three executives of selling because they learned of the breach.

“The Justice Department may believe there is a culture of lax enforcement and lax policing at this company,” Nick Gravante, a white-collar criminal defense lawyer and partner at Boies Schiller & Flexner, told The Post.

“It could be that this is the beginning of trying to get someone who is a lower-level employee to implicate others who may be involved,” he added.

Gravante has no connection to the Equifax case.

Equifax spokeswoman Ines Gutzmer declined to comment on any speculation.

In the latest insider trading case, Sudhakar Reddy Bonthu is charged with buying Equifax put options after learning of the data breach.

When the breach was disclosed to the public — which resulted in the personal info on 148 million Americans being stolen — Equifax shares tumbled and Bonthu was sitting on $75,000 in profits, it is alleged.

Bonthu, 44, a software engineer brought in to work on improving Equifax’s cyber defense, was not told of the breach but gleaned info about the cyber attack from documents he was working on, court papers allege.

“Bonthu allegedly took advantage of his position to profit while members of the public were unaware of the data breach at Equifax,” Atlanta US Attorney Byung J. Pak said in a statement.

The Securities and Exchange Commission has filed parallel civil charges.

Bonthu was arraigned on Thursday.

In March, Jun Ying, Equifax’s former chief information officer, was charged with insider trading. He sidestepped losses by selling more than $1 million in stock after finding out about the breach — and before the public was alerted.

Equifax shares gained 2.6 percent on Thursday, to $126.16 — but are still far below the $142 price the day before the breach was disclosed.