Eastern Province coach Peter de Villiers and 11 of his players have tested positive for Covid-19, the union has confirmed.
A letter from president Andre Rademan to the EP executive committee, the region's clubs and all EP staff was posted on social media on Tuesday.
Rademan confirmed that the EP offices would be closed until 14 June.
He added that a friendly match between the EP Elephants and Griquas, originally planned for Saturday 12 June, had been postponed.
EP are due to compete in the second tier of the Currie Cup - the First Division - this year, which is due to get underway on 19 June.
This latest development, however, throws EP's participation in the opening weekend of the competition into doubt.
@CoachPdV and 11 players test positive for COVID-19 ???? pic.twitter.com/pxZMkbuKny
— EP Elephants (@ep_elephants) June 8, 2021