MK David Bitan (Likud) announced on Monday that he had contracted COVID-19, shortly after his adviser was reported to have contracted the virus.
"In the test I did today I was found to be positive for the coronavirus. I feel fine with only mild symptoms," Bitan wrote on Twitter.
An earlier test conducted on one of Bitan's advisers found that he was also positive for coronavirus.
The adviser was last at the Knesset this past Wednesday, together with Bitan.
The Knesset continues to work on conduction an epidemiological examination and investigation together with the health authorities.
Prime Minister Binyamin Netanyahu will not go into isolation despite coming into contact with MK Bitan at a ceremony last week.
His office said that Netanyahu had been in the vicinity of Bitan for less than a quarter of an hour and therefore did not have to be quarantined.
However, coalition chairman MK Miki Zohar, who met with Bitan last Thursday, will go into isolation, as will Likud MK Ofir Katz.