Australian rugby officials will ask the game's governing body if All Black Jonah Lomu has been given special dispensation to take banned medication to deal with a kidney complaint.

"Our understanding is that might be the case - we're trying to find out," Australian Rugby Union general manager John O'Neill told The Australian.

"But we've asked the Kiwis and you don't get much in the way of response." He said the ARU would ask the International Rugby Board to clarify the issue.

Lomu began treatment four years ago for a cancer-threatening kidney ailment that might have included drugs on rugby union's prohibited list, the paper said.

The awesome All Black winger burst onto the world stage in 1994, but was diagnosed with Nephrotic Syndrome, a rare kidney disorder, in late 1996. He was out of the game for 12 months.

According to the paper, Lomu was, at one stage, taking 14 tablets a day to keep the condition under control, but has since cut it down to two.