Gardai are waiting to gather further evidence before interviewing the driver of the bus involved in the Co Meath crash which left five school pupils dead and 46 injured.
The scene of the crash involving a CIE Bus Eireann coach and two cars on the Kenstown Road, near Navan
The investigation team, which has already interviewed the surviving pupils on the Navan-Kentstown road, have to date only spoken informally to the driver.
They also have to speak to the female driver of a car involved in the crash who is still in hospital. Five teenage girls were killed when the bus overturned last week.
More than 100 statements have been taken as part of the Garda investigation. Supt Gerry Smith who is heading the investigation said officers were continuing to investigate all circumstances surrounding the accident, including driver behaviour and the condition of the road.
The Alexander Reid to Follistown stretch of the R153 road where the bus overturned was being resurfaced at the time. The road has now been closed for completion of the works after the Health and Safety Authority (HSA) issued a prohibition notice to Meath Co Co last week to halt the works after it found no safety plan or project construction supervisor in place.
A HSA source said prohibition notices were only issued when there was a serious threat to life. The Council was also served with an improvement notice, setting out the work which had to be undertaken. Both notices were complied with and the HSA has given permission for roadworks to resume. The road is due to reopen on Friday.
Supt Smith also issued an appeal for a lorry driver who was at the scene of the crash to come forward. The Garda is asking him, or anyone who knows him, to contact them at 046 9079930.
They believe the lorry was the kind that transports sand or gravel but have no further information.
Supt Smith said there was no suggestion that the driver was involved in the accident but added that he might have vital information.
"He was supposed to be stopped at the traffic lights on the Navan side driving a sand lorry. We've accounted for everyone else that was in the vicinity at the time but we can't account for this person."
Fifty two pupils and the bus driver were treated for injuries following the crash on May 23 rd. The bus was bringing pupils home from four schools in Navan at the time. Five girls died in the crash that has led to calls for safety belts to be fitted on all school buses.