Richmond Federal Reserve President Jeffrey Lacker’s leak of sensitive information in 2012 could have come about as a consequence of a “mind lapse”, according to one of his former colleagues.

Former Atlanta Federal Reserve President Dennis Lockhart told CNBC Wednesday that the incident was “regrettable”.

“I don’t know the details but it could very well be inadvertent. It could be something that is sort of a mind lapse at a moment that you are not thinking,” Lockhart told CNBC when asked to comment on Lacker’s resignation.

“It was a few days before the minutes were to come out and so the leak as I recall … The leak involved disclosing information in advance of the minutes which of course is a no no. Jeff for me has been a very valued colleague for many years so I just think this is a regrettable set of circumstances,” he added.

Lacker tendered his resignation on Tuesday after admitting he had discussed sensitive information about Fed policy options with a Wall Street analyst in 2012. In Lacker’s letter of resignation, he admitted speaking to an analyst at Medley Global Advisors regarding the September 2012 Fed meeting. Medley publishes analysis for hedge funds and asset managers and is owned by the Financial Times.

Lacker said he had “crossed the line” when discussing sensitive information with a Medley analyst and that his actions violated Fed communications policies which prohibited “providing any profit-making person or organization with a prestige advantage over its competitors.”

The former Richmond Fed President had been known as one of the most reliable proponents for U.S. interest rate hikes during his tenure.

— Jeff Cox contributed to this report