Aboriginal academic Marcia Langton has written a 19-page essay clarifying "the nature of her apology" to controversial columnist Andrew Bolt, and again raising the spectre of his views on race.

The statement, which runs close to 5000 words, was published on the ABC's Q&A website after host Tony Jones issued an apology on Monday night for broadcasting comments made by Professor Langton during the previous week's program.

Last Monday, Langton said Bolt had heaped "foul abuse" on indigenous woman Misty Jenkins, which had led to her withdrawal from public life.

Langton later backed down from her comments in an interview with Bolt and radio broadcaster Steve Price on 2GB on Wednesday.