Anti-virus software creator John McAfee has said he will break the encryption on an iPhone that belonged to San Bernardino killer Syed Farook.
Mr McAfee made the offer to the FBI in an article published by Business Insider.
Apple has refused to comply with a court order asking it to unlock the device, dividing opinion over whether the firm should be compelled to do so.
Mr McAfee said he and his team would take on the task "free of charge".
The offer came as Mr McAfee continues his campaign as a US presidential candidate for the Libertarian Party.
"It will take us three weeks," he claimed in his article.
Security expert Graham Cluley told the BBC he was sceptical of Mr McAfee's claims.
"The iPhone is notoriously difficult to hack compared to other devices," he said.
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John McAfee offers to unlock killer's iPhone for FBI - BBC News