The Scottish Information Commissioner has backtracked on her decision to force Scottish ministers to name the salmon farms that shoot seals to stop them eating fish.

In a rare move, Rosemary Agnew has reopened her investigation into the issue because of new allegations from salmon netters, who also shoot seals. They claim to have had threats from animal welfare groups, including a death threat.

Agnew has now given ministers until the end of the month to provide hard evidence of the risks to property and people. She will then consider whether to enforce her decision, which originally demanded seal-shooting salmon farms be identified by January 10.

Her change of heart was due to the "seriousness of the concerns raised", according to an email last week from her office to the Global Alliance Against Industrial Aquaculture (GAAIA), which had asked for the sites to be named under freedom of information law.

The Sunday Herald revealed on December 2 that Agnew had dismissed the Scottish Government's arguments for continued secrecy as "tenuous". Ministers had failed to provide sufficient evidence to back up fears that shooters could be endangered, she said.

But now she is giving them a second chance to make their case. She has been told by the Salmon Net Fishing Association of Scotland that identifying shooting sites "will materially affect the safety of our members and could potentially result in significant harm to them personally, or to the equipment."

GAAIA's Don Staniford said the Scottish Government was "desperately squirming off the hook". It smells "decidedly fishy", he claimed. "It appears illogical and unreasonable that a last-minute complaint by netsmen has any bearing at all in relation to a freedom of information request on salmon farms."

Agnew's U-turn has also been challenged by John Robins, secretary of the Save Our Seals Fund. He found it "extremely difficult" to accept the netters' concerns, as the only details that would be released would be historic and would not identify individuals.