A senior Morrisons worker was accused in court of holding a "grudge" against the supermarket after allegedly leaking the details of 100,000 staff members.

Andrew Skelton, a 43-year-old IT auditor at the firm’s Bradford head office, was said by prosecutors to have sent packages containing the data to three newspapers, including The Daily Mirror and the Guardian, with the leak taking place last May.

He is also alleged to have uploaded data to a sharing site.

Prosecutor Katherine Robinson claimed in Bradford Crown Court that this was in response to a warning from Morrisons over Skelton’s purported use of the firm’s mail room to send eBay packages.

According to Robinson, one package Skelton sent through the firm’s mailroom was initially believed to have contained drugs, a notion later found to have been wrong when it was handed to the police.

"He was allowed to continue with his employment," Robinson said, according to the Liverpool Echo.

"The prosecution case is that as a result of that disciplinary matter the defendant bore a grudge against Morrisons…which led to his offending in this case."

Among the data Skelton is alleged to have leaked were National Insurance numbers, bank account details, dates of birth, salaries and addresses.

Morrisons claims that his actions cost the company £2m to fix.

Skelton denies a count of fraud by abuse of position, a count of unauthorised access to data with the intent of committing an offence, and a count of disclosing personal data.

The trial continues.