In March 2014, the trust inadvertently published confidential data including national insurance numbers, dates of birth, religious beliefs and sexual orientation.

The trust did not notice its mistake for 10 months and it was another five months before they informed affected staff.

Stephen Eckersley, head of enforcement at the Information Commissioner’s Office, said: “This trust played fast and loose with the highly sensitive and private information that was entrusted to them. It seems they ignored their duty to put rules in place to protect staff who deliver hospital services to others.”

Related content

Laptop theft leads information watchdog to act against Scottish council
Invigorating the public sector revolution

He said that measures to protect the information from being published were “woefully inadequate or non-existent”.

Staff agreed to provide the  information as part of the trust’s promise to publish equality and diversity metrics online.

But the trust used spreadsheets which revealed hidden data when users double-clicked on the data.

The ICO issued fines in similar circumstances against Torbay NHS Trust in July 2012 and London Borough of Islington in August 2013.

Last week, the ICO announced that the Culture, Media and Sport select committee had approved Elizabeth Denham as the new Information Commissioner.

Subject to final approval from the Queen, Denham will take over from incumbent Christopher Graham in summer 2016.