An anonymous hacker claimed to have broken into the presumptive Republican presidential nominee's personal e-mail account, allegedly by guessing the answer to the security question, "What is your favorite pet?" and then changing the password, McClatchy News Service reported.
While claiming to have breached Romney's personal accounts to Gawker, the alleged hacker did not include screen shots as proof.
Gawker said it didn't try to access the account, but did alert the Romney campaign, McClatchy reported.
"The proper authorities are investigating this crime and we will have no further comment on it," the campaign said in a statement.
The e-mails from Romney's gubernatorial administration were obtained through a Freedom of Information request by The Wall Street Journal, which sought missives involving several officials, including Tom Trimarco, Romney's administration and finance secretary.
When Romney left the governor's office, his staff erased all the e-mails so correspondence would remain out of the public eye, ABC News reported. Trimarco, however, never deleted his e-mails.
In an interview with ABC News, Trimarco said he didn't know he was supposed to delete them.
"No memo ever came around advising that was an option," he said. "So when I left, I just left ... ."
One e-mail was a note Romney sent to Trimarco on the night the night the governor signed the healthcare bill into law.
"You have made a huge difference, for me and for hundreds of thousands of people who will have healthier and happier lives," Romney wrote on April 12, 2006.
Trimarco said the e-mails show Romney cared about providing healthcare for Massachusetts residents because "his fingerprints are all over this thing."
Trimarco bemoaned Obama's healthcare law being enacted on a national scale despite some good aspects, and also ripped Republicans for opposing the mandate, which he said draws on the GOP principle of "individual responsibility."
"I understand the Republican Party on a national level has now made this a cause celebre ... that this individual mandate makes you un-American and not a worthy Republican," Trimarco told ABC News,. "and old-timers like me don't get it."
ABC News said the Romney campaign declined to comment.
Romney has defended the e-mail deletions by arguing they would be grist for political opponents.
John Wonderlich, policy director at the Sunlight Foundation, which advocates for open government, criticized Romney for citing political reasons to keep the e-mails secret.
"That's the most explicit statement of Governor Romney treating public records as fundamentally campaign materials," Wonderlich told ABC News. "The way we should view public records is not through the lens of a campaign, as he did, but through the lens of a government that serves the people's interest."