US Attorney General Eric Holder on Wednesday testified in the House of Representatives over the Justice Department's decision to subpoena journalists' phone records in connection with a leak investigation, and he denied knowledge of the controversy.

Holder, who said Tuesday that he had recused himself from the leak inquiry, offered little insight to lawmakers on the House Judiciary Committee, saying he doesn't have "a factual basis to answer the question because I was recused."

Holder also said he knew nothing of the details involving the controversy, saying "this is an ongoing matter and also an ongoing matter about which I know nothing." But he did offer to give an explanation once the investigation is concluded.

Lawmakers, however, seized the opportunity to criticize Holder and the Justice Department. Committee Chairman Bob Goodlatte said the Justice Department's handling of the investigation "appears to be contrary to the law and standard procedure."

The phone records seizure controversy broke on Monday. The Associated Press (AP) said more than 20 telephone numbers' records spanning two months were secretly subpoenaed by the Justice Department and the numbers were used by AP reporters and offices in Washington D.C., New York and Connecticut.