The report by Steve Marshall was discussed on Saturday by a key committee of the ILO, at its annual conference being held in Geneva.
An estimated 2.4 million people remain homeless and hungry from the May 2-3 cyclone, which left at least 134,000 people dead or missing.
Appeal to rulers
The committee said it hoped the reconstruction work is done without the use of forced labour. It urged the military government to increase efforts to implement a complaint mechanism the ILO set up with the junta in February 2007.
The mechanism allows victims of forced labour to submit complaints to the UN agency with the guarantee that "no retaliatory action" be taken against them.
"The exaction of forced labour continued to be widespread particularly by the army," the ILO committee said in its conclusions, adding that the recruitment of children into the army was a major concern.
The conclusions are expected to be formally adopted by the ILO conference on June 13.
"At this stage we have not received any complaints of the use of forced labour or the use of child labour in regard to the cyclone reconstruction activity," Marshall said.
But "in any disaster of this kind, the risk of abuses of that nature increases", he told The Associated Press, adding that displaced people and women and children who have lost their families are particularly vulnerable.
"The risk is very high," Marshall said.