poreći

1. to deny
   Ministar je porekao sve navode iz novina. — The minister denied all the claims in the papers.
   Ne može se poreći da je bila u pravu. — There's no denying she was right.
2. (of one's own words) to retract; to take back
   Svedok je na sudu porekao svoj raniji iskaz. — In court, the witness retracted his earlier statement.

The imperfective is poricati; a common construction is ne može se poreći da… "there's no denying that…".