The hero hacker credited with stalling WannaCry had been due to appear in court today to answer cyber crime charges related to separate malicious software.

But Marcus Hutchins’ arraignment, during which he had been set to enter a plea, has now been postponed till 14 August.

Prosecutors said in a hearing on Friday that he had admitted to writing the code behind Kronos malware, a trojan that harvests victims’ bank account passwords. But after the hearing, his lawyers said he denies the charges.

When Hutchins’ arrest hit the headlines last week, IT security consultant Robin Edgar told Radio 4’s Today Programme: “Mr Hutchins posted a tweet saying, ‘look, this Kronos thing has taken my code, stolen my code and used it in it’.

“He was very unhappy his code had been stolen and used within Kronos. He didn’t write Kronos, it looks like, but he wrote a little piece of code which was used in the malware.”

Hutchins’ mum, Janet Hutchins, told the Press Association it is “hugely unlikely” he was involved because he spent “enormous amounts of time” fighting attacks.