A police chief with responsibility for the unit that unlawfully spied on journalists’ sources has applied to take over from Stephen House as head of the single force.

Neil Richardson, dubbed the “force disciplinarian”, is believed to have made an approach for the chief constable’s post last week.

Richardson joined Lothian and Borders Police in 1985 in what was his first role in a twenty-year career in the now-defunct Edinburgh force.

He held positions in community safety, firearms and CID before getting a secondment to the Scottish Crime and Drug Enforcement Agency (SCDEA).

In 2008, he left L&B for Strathclyde Police, where he became deputy chief constable in charge of areas such as professional standards and discipline.

He was awarded the Queen’s Police Medal in 2011 and became Deputy Chief Constable (Designate) for Police Scotland in 2012.

However, he has portfolio responsibility for one of the key issues that have dogged the single force.

Since March 25, police forces have required judicial approval before using surveillance legislation to flush out a journalist’s source.

The law change followed widespread concerns about police officers using the Regulation of Investigatory Powers Act to unmask confidential contacts.

A surveillance watchdog disclosed in July that two unnamed forces had breached the new Code on judicial permission.

One of the violations was committed by Police Scotland’s Counter Corruption Unit (CCU), which falls under Richardson’s control. He has yet to say anything on the spying row.

The post of Chief Constable of Police Scotland is the second biggest job in UK policing after the Commissioner’s job at the Metropolitan police.

Deputy chief constable Iain Livingstone is another officer tipped to apply.

On Monday, when details of the appointment process were announced, Scottish Police Authority chair Andrew Flanagan said: “Our police workforce has spoken recently about their experience of the new policing arrangements. There are things we need to improve.

"All those shortlisted for the job can expect to be challenged on how they would personally address the central issues within the recent workforce survey.”

Scottish Conservative chief whip John Lamont said: “Police spying on journalists is quite simply not something that can be tolerated in any society which claims to be modern. As such, it’s important whoever secures the top job within Police Scotland makes this very point. We’re lucky to have a free press in this country, and that’s something the Scottish Government ought to value as well.”

A Police Scotland spokesman said Richardson declined to comment.