The case of British cybersecurity expert once heralded as a hero for stopping the WannaCry worldwide computer virus has been delayed.

The move came to allow his lawyers more time to prepare arguments on why a judge should suppress statements he made after his arrest for allegedly creating software to steal banking passwords.

Marcus Hutchins, 23, pleaded not guilty after his arrest last year in Las Vegas before he boarded a flight home to England.

US prosecutors say Hutchins created and distributed malware known as Kronos and made incriminating statements to FBI agents after his arrest and in two phone callsfrom jail.

Federal prosecutors publicly revealed details of those phone calls for the first time in court filings on Wednesday night, and provided Hutchins’ defence with new transcripts of the conversations.

Hutchins’ lawyer, Brian Klein, told a federal magistrate judge that prosecutors intended to present those calls in court on Thursday to “make assertions about what he said and the significance of those” conversations.

The hearing was rescheduled for May 16.

Hutchins’ August arrest came as a shock, as four months earlier, he was lauded as a cybercrime-fighting hero for finding a “kill switch” to slow the outbreak of the WannaCry virus, which crippled computers worldwide, encrypting files and making them inaccessible unless people paid a ransom.