Man jailed for sex attack on mother

A Northern Territory man who had sex with his mother has been sentenced to three years' jail but will be eligible for parole this month.

The 26-year-old man pleaded guilty to having sex with his biological mother twice earlier this year while he was affected by alcohol and other drugs.

Justice Sally Thomas said the victim was suffering from a debilitating illness requiring a wheelchair, which made her vulnerable.

The prosecution asked for a penalty that would serve as a general deterrent.

But the judge said while the case affects public morals and community standards it was extremely rare and she could find no precedent in the Northern Territory.

The man was sentenced to three years in prison, eligible for parole after six months.

He has already served more than five months in jail and could be released at the end of this month.