CNN  — 

The Trump Organization’s corporate director of security is expected to appear before a grand jury on Thursday in Manhattan, where prosecutors are investigating former President Donald Trump’s business, according to a person familiar with the matter.

The executive, Matthew Calamari Jr., was served a subpoena to testify, and he is expected to appear to answer questions before the grand jury, the source said. Calamari Jr. is the son of the company’s chief operating officer, a longtime Trump deputy who is also under scrutiny by prosecutors in the Manhattan district attorney’s office.

The Wall Street Journal was first to report on Calamari Jr.’s expected grand jury testimony.

Under New York state law, Calamari Jr. will be granted transactional immunity on the subjects he testifies about. The decision to bring him before the grand jury signals prosecutors do not plan to indict him.

A spokesman for the Manhattan district attorney’s office declined to comment.

In July, the district attorney’s office charged the Trump Organization and Chief Financial Officer Allen Weisselberg with a 15-year alleged tax scheme, saying they systematically avoided paying payroll taxes and income taxes on fringe benefits including rent-free apartments, cars and private school tuition. They pleaded not guilty.

Since prior to the indictment, Calamari Jr. and his father have faced questions by prosecutors about whether they properly paid taxes on subsidized rent and cars they received as benefits from the company, CNN has previously reported.

In recent weeks, the district attorney’s office has been pressuring Matthew Calamari Sr., known to be a fiercely loyal employee of the former President, to cooperate, and discussions between prosecutors and his lawyer have continued, the source said.