Mr Langley said New Zealand had since been given "strong and direct" signals from the Saudi government that the partnership with the Al Khalaf Group had removed "a significant stumbling block" to a free trade deal with the Gulf states.
After the committee, Labour's foreign affairs spokesman David Shearer told reporters he doubted whether the agrihub played any part in progress towards an FTA. He said the progress made by New Zealand was more likely the result of improving global economic conditions.
"The fact that we have spent so much money on Saudi Arabia is irrelevant. What we have effectively done is paid a facilitation payment to a businessman in order to try and get his favour.
"That's an extraordinarily long way around and an extraordinary cost to try and get a free trade deal."
Mr Langley also said the agrihub "unlocked opportunities" for New Zealand companies. The abattoir promoted New Zealand's capabilities at a time when the Saudi government was looking to upgrade or replace 2000 abattoirs.
"It creates an economic opportunity for us," Mr Langley said.
About $11.5 million has been spent on sending New Zealand sheep and equipment to Saudi Arabia, with $6 million of that spent on establishing a farm, including equipment and technology.
Mr Langley said he did not know how many MFAT staff were working on the project.
But he noted that "a number of" policy advisers had been required to process 39 Official Information Act requests and 200 Parliamentary questions about the agrihub.