Israel Police is reportedly looking into allegations that employees at Israeli Aerospace Industries who refused to register as members of the Likud party may have been systematically denied promotions or raises in salary, and in some cases were even fired.

“We knew about the phenomenon of registering to the Likud party under duress,” said a senior investigator, according to Israel’s Channel 2 Friday. “But we did not expect that we would encounter it with such intensity.”

The allegations of staffers being required to register for the Likud were among a number of alleged corrupt practices police have been investigating at the firm.

The Channel 2 report said that the name of Haim Katz, the Likud’s social affairs minister who previously served as head of the IAI works committee, had been mentioned by some workers in testimony to police, but that there was no evidence to link him to any criminal activity.

Social Affairs Minister Haim Katz attends a Labor and Welfare committee meeting in the Knesset, June 08, 2015. (Alster/FLASh90)

Social Affairs Minister Haim Katz attends a Labor and Welfare committee meeting in the Knesset, June 08, 2015. (Alster/FLASh90)

In a statement, Katz said no such corrupt practices went on under his watch, and that there was a “witch-hunt” under way to harm his reputation.

Earlier this week, 13 people were arrested at the defense contractor for “irregular” activities, and the IAI said that it had been conducting its own internal probe into various suspicions.

“At the instruction of [IAI] CEO and the board, the company acted to verify and handle a number of suspicions, with a zero-tolerance approach toward unacceptable conduct,” the IAI said in a statement Wednesday.

IAI said that the results of the probe were submitted to law enforcement authorities.

The arrests of the 13 people, including a former high-ranking IDF officer, came as part of a months-long covert police investigation into “widespread corruption” at the company.

Judah Ari Gross and Adiv Sterman contributed to this report.