Veteran ABC rugby league commentator David Morrow says he is "ashamed and embarrassed" for making an on-air racist joke to a fellow broadcaster.
Morrow was suspended after making the joke shortly before ABC Grandstand's scheduled broadcast of the St George Illawarra-Manly match on Monday night.
The veteran commentator, who has 40 years of broadcasting experience, was heard joking about how hard it was to see people in Darwin without the lights on.
Morrow did not realise that he was on-air at the time.
He told NITV that he apologises for any offence he has caused Indigenous Australians.
"Of course I'm embarrassed. I'm ashamed ... I'm quite distressed," he said.
"I most unreservedly apologise for any sort of offence I've caused any member of the Indigenous Australian people of this country.
"More importantly, if I offended anyone, it's a disgrace and I deserve a proper kick in the teeth for doing so."
ABC Grandstand Sport manager Craig Norenbergs said the matter is under investigation and Mr Morrow remains suspended pending its finalisation.
"ABC Radio takes the issue of discrimination and prejudice extremely seriously," Norenbergs said in a statement.
"The matter is being investigated in line with ABC Editorial Policies and Code of Conduct."
The Australian Rugby League Indigenous Council chairwoman Linda Burney expressed her disappointment over Morrow's comments.
"I think he deserves some very rigorous punishment for this and I leave it up to the ABC to decide what the outcome is," she said.
Morrow has also issued a statement apologising for the incident. The statement was not released in consultation with the ABC and was not seen by the broadcaster before its release.