Deputy Chief Constable Neil Richardson is to give evidence to members of the Scottish Parliament’s Justice Committee.
MSPs will also get the chance to question John Foley, the chief executive of the Scottish Police Authority, and Justice Secretary Michael Matheson.
Opposition politicians have been demanding answers ever since Sir Stanley Burton, the Interception of Communications Commissioner, said in a report last month that Police Scotland had contravened the Acquisition and Disclosure of Communications Data Code of Practice on five occasions.
The Interception of Communications Commissioner’s Office (IOCCO) conducted a review after fears were raised that officers had been ‘illegally spying on journalists’.
Those five incidents are all said to be linked to the investigation into the murder of prostitute Emma Caldwell.
Two days ago it was claimed that officers had also made seven applications to acquire communications data relating to journalistic sources between 2011 and 2014.
The Scottish Newspaper Society said it had uncovered the attempts using freedom of information laws.
Police Scotland Assistant Chief Constable Ruaraidh Nicolson said: “Of the seven identified investigations, four pre-date the formation of Police Scotland on April 1 2013. Six of these applications were authorised and one refused.
“None of these seven applications concerned a journalist, and the six applications were legally and appropriately authorised under the Regulation of Investigatory Powers Act 2000 and were later the subject of IOCCO inspection in the usual way.”