Illicit drugs were detected in the blood of a truck driver accused of hitting a school bus and killing a nine-year-old boy in the NSW Hunter, court documents allege.

It is also alleged that Daniel Ronald Hennessy, 35, of Regents Park, Queensland ran a stop sign before hitting the bus.

He is charged with dangerous driving and negligent driving causing the death of Harry Dunn in Kelso Street, Singleton, on September 10 last year.

He is also charged with driving a Kenworth prime-mover truck at the time with prescribed illicit drugs, amphetamine and methylamphetamine, in his blood.

In an initial mention before Singleton Local Court on Thursday, magistrate Ron Maiden said he had received a letter from Hennessy's legal representatives seeking an adjournment and a copy of a police evidence brief.

Hennessy was not before the court, is not constrained by bail and has not been required to indicate pleas to the charges.

Mr Maiden adjourned the case to Newcastle Local Court on May 8 and directed investigating police to complete a brief for the prosecution and defence by April 24.

Members of Harry Dunn's family were in the courtroom for the brief proceedings.