Al-Dahlaki said the compromised meal served for iftar, which marks the breaking of fast during Islam's holy month of Ramadan, included meat, rice, yogurt, a bean sauce and water.
"Staff have been working closely overnight to coordinate the response with other agencies and the relevant authorities.to ensure that those who have fallen ill were able to receive swift medical treatment and that the seriously sick were provided transport to nearby hospitals", the statement said.
Al-Dahlaki said the food was distributed by RAF, adding that Iraqi officials were to meet those from the organization later Tuesday.
Children and elderly were the most affected, complaining of vomiting and stomach-aches.
Qatari government officials also did not immediately respond to a request for comment.
On Twitter, Saudi state television accused RAF of supplying tainted meals and posted images it said showed the camp's children "poisoned by the terrorist Qatari RAF organization".
Thirteen camps have been established by the UNHCR to deal with the flow of the internally displaced people fleeing the city.
But later in the day, United Nations refugee agency the UNHCR said there had not been any deaths.
Iraqi forces repelled a major counter-attack by Islamic State fighters, many of them wearing suicide vests, in a district south of the Old City of Mosul, their remaining enclave in the city, at dawn on Wednesday, a police commander said.
The extremists now only control a handful of neighbourhoods in and around Mosul's Old City, located west of the Tigris River, which divides the wider city into its western and eastern sectors.