ABC News anchor George Stephanopoulos failed to disclose his past donations to the Clinton Foundation during an interview with Democratic presidential frontrunner Hillary Clinton on Sunday.

Stephanopoulos’ interview with Clinton on ABC’s This Week covered a range of issues, but he never mentioned his connections with the Clinton family.

"And Hillary Clinton joins us now from Los Angeles. Madame Secretary, thank you for joining us this morning," Stephanopoulos said at the start of the interview before asking his first question.

He never disclosed to viewers that he has given large sums of money to the Clinton Foundation.

The Washington Free Beacon reported in May 2015 that Stephanopoulos gave $75,000 to the foundation.

ABC issued an apology after the Free Beacon story was published but refused to take further action.

It is common practice for journalists and commentators to disclose any connections they may have with political candidates while discussing them or their campaigns on air.

An ABC News spokeswoman told the New York Times last year that "an employee making a donation to a charity must ‘disclose that to us before covering a story related to that organization.’"

Stephanopoulos has conducted several past interviews with Clinton and stopped disclosing his donations to her family’s foundation.

The Republican Party blocked Stephanopoulos from moderating a GOP presidential primary debate on ABC last year, citing a conflict of interest, although the news anchor spoke on air before and after the debate.

Stephanopoulos also did not tell viewers on Sunday that he is a former aide to former president Bill Clinton.