In a statement dated August 4 but posted on its website on Thursday, the AU's Peace and Security Council said it "commends the AU High Representative for the direct engagements between the Government of the Federal Democratic Republic of Ethiopia and the Tigray People's Liberation Front (TPLF)".
But an updated version of the statement on the website has replaced the word "between" by "with" and the original, which was published in both English and French, is no longer available.
AFP has contacted the PSC for comment but there was no immediate response.
Getachew Reda, spokesman for the Tigray People's Liberation Front (TPLF), said an AFP story that cited an AU statement was "pure fabrication".
"Such engagement simply didn't happen!" he said on Twitter.
Government forces have been at war with the TPLF since November 2020 but in recent weeks both sides have mooted the possibility of peace talks.
Prime Minister Abiy Ahmed's government wants any negotiations to be led by the AU, but the rebels want Kenya's outgoing President Uhuru Kenyatta to mediate.
TPLF leader Debretsion Gebremichael has also insisted that key services would have to be restored in Tigray before dialogue could begin.
In its statement, the AU council called on the warring sides "to place the supreme interests of Ethiopia and its people above all else and embrace inclusive political dialogue as the only viable approach towards finding a consensual solution to the current situation".
It also urged international partners to support AU-led mediation under former Nigerian president Olusegun Obasanjo "as the only viable and effective approach towards finding a negotiated lasting solution to the situation in Ethiopia".
Fighting has eased in northern Ethiopia since a humanitarian truce was declared at the end of March, allowing the resumption of desperately needed international aid convoys to Tigray's six million people.
Since the war broke out, Ethiopia's northernmost region has suffered food shortages and access to basic services such as electricity, communications and banking has been severely limited.
In November 2020 Abiy ordered troops into Tigray to topple the TPLF, accusing the rebels of attacking federal army camps.
The TPLF mounted a shock comeback in June last year, retaking Tigray and expanding into neighbouring Afar and Amhara, before the war reached a stalemate.