The controversial backbencher, who is a leading critic of the Islamic certification of food and set up a contentious Senate inquiry into the issue, has demanded answers from the AIS about its halal policies in its dining hall.

In a series of "questions on notice" that have just been made public, the South Australian politician called on the AIS to explain an information manual that says all its dining hall meats are halal certified.

The manual has stoked online controversy among halal opponents. A "Boycott Halal in Australia" Facebook page that has more than 80,000 likes calls the AIS policy "outrageous". Earlier this year readers of Senator Bernardi's blog urged him to get to the bottom of it.

Critics were particularly incensed that halal food appeared to be provided as standard but kosher food could be provided only on request and incurred very high additional costs, a point Senator Bernardi takes up in one of his questions.

"Does the AIS acknowledge that there appears to be a discrepancy in religious food requirements, between the provision of food for Muslim athletes and the provision of food for Jewish athletes?" he wrote.

But the Australian Sports Commission, which is responsible for the institute, said the manual was not strictly accurate. A spokesman for the ASC said while meat supplied in the dining hall came from a halal-certified supplier, the institute had not specifically requested halal-certified products.

"The AIS has now amended its dietary guidelines to reflect this," the spokesman said.

The AIS can cater for halal requirements on an "as needs basis" – the same approach it takes to kosher food.

Halal meat has been requested by some clients following the changes. "The AIS apologises unreservedly to people who have unknowingly consumed food that was not halal certified at the AIS," the spokesman said.

Senator Bernardi's inquiry into "third party certification of food" has attracted a flood of sometimes bizarre and hateful submissions.

The inquiry received around 600 public submissions before the July 31 deadline, many of which contained vicious attacks on Muslims and the Islamic faith. It is due to report to parliament in November.