The Australian Federal Police regretted this error and had apologised to Seven.
The officer responsible had been counselled, he said.
"There is enough for us to continue our investigation to see whether or not we should issue a proceed of crime [action]," he said yesterday.
Corby, 36, spent more than nine years in jail in Bali after being found guilty of importing marijuana.
She was released on parole on February 10 and promptly whisked away to a luxury resort.
Phelan said that gave good reason to suspect a media deal involving Seven - $2 million, according to initial speculation but now thought to be about $500,000 - was planned.
"I would be quite happy if she does an interview. She just can't be paid for it," he said.
Phelan said that in previous proceeds-of-crime action over the Corby book My Story, some $100,000 was seized but a larger sum was moved overseas.
Seven Network commercial director Bruce McWilliam said its next step would be the Federal Court tomorrow to have the search warrants set aside.
"When they make such a basic error as that, you wonder what else is wrong," he said.
McWilliam did not deny Seven was seeking an exclusive interview but said there was no deal yet and the Australian Federal Police were getting ahead of themselves.
"If a reasonable fee is asked for, that would be a negotiation. I am not saying we wouldn't agree to it," he said.
"We have been negotiating obviously for a long time. [Television presenter] Michael Willesee is not up there for a holiday."
McWilliam said the only signed agreement was with Mercedes Corby to arrange an interview. For that she had been paid some $25,000.
"Sure, there's an expectation that money might have to be paid. We are not denying that," he said.
"We haven't done a deal. All the media outlets are after it."
- AAP
