A Canberra man has pleaded guilty to supplying cocaine to rugby league stars Kevin Proctor and Jesse Bromwich after the Anzac test in the capital earlier this month.

Adrian Mark Crowther, 45, was caught after CCTV allegedly captured him prepare a white powder on his phone that was then snorted by two other men through a rolled bank note.

It was about 5.10am on May 6, and ACT Policing had been monitoring Civic's surveillance videos. Officers later went to the scene at Petrie Plaza, near Cube nightclub, and found the man with the phone.

The man, who police identified as Crowther, was wearing an All Blacks scarf, documents tendered on his last appearance said.

The Kangaroos had beaten the Kiwis by 30-12 at GIO Stadium the night before.

While both Kiwi players have been named in court, police have not laid charges on either.

But the fallout for the two players was swift.

The following day Jesse Bromwich stood down as New Zealand rugby league captain and missed two matches for his club the Melbourne Storm after apologising for his "poor choices" in Canberra.

Kevin Proctor, declaring himself "extremely embarrassed and sorry", later stood down as co-captain of the Gold Coast Titans.

Both player lost their places in the Kiwi's World Cup team for France later this year, after coach David Kidwell said they had broken his trust.

Crowther appeared briefly in the ACT Magistrates Court on Monday where he entered pleas of guilty to possessing cocaine and MDMA, and supplying cocaine.

The case will return to court on July 31 for sentence.