Millers failed to import the full quantities of maize that the Treasury allowed them to ship in as the lower duty window closed at the end of last month.
The government had allowed millers to import four million bags of white and yellow maize to address the shortage that had been anticipated.
However, data seen by the Business Daily indicates that millers have only managed to ship in 1.2 million bags.
They were allowed to import white maize at 14 percent duty and the yellow variety at 10 percent duty. Normally imports outside the East African Community would attract a 50 percent duty.
Data from the Kenya Ports Authority (KPA) shows millers brought in three shiploads, with the first one that arrived on June 14 carrying 386,666 bags of maize.
On July 27 a second vessel- IVS Tembe, arrived with 333,333 bags of the produce, while Kavo Pedika docked with 488,888 bags on July 18.
The data from the port indicates that of the 1.2 million bags of maize that was imported, white maize accounted for 822,221 bags.
Millers said a court case by activist Okiya Omtatah was the reason why most of them did not import the grain.
“When the court stopped imports, we had to be cautious as we did not know how long the case would last keeping in mind that there was a short window to do the shipment,” said a miller who sought anonymity.
Mr Omtatah argued there were errors in the gazette notice that was published by the Treasury.
For instance, the gazette notice had instructed millers to import maize with aflatoxin levels that do not exceed ten parts per million, when the required standard is 10 parts per billion.
The error was, however, rectified in the gazette notice that was published in May, which extended the import window by two months.
Some millers also failed to collect the maize that has landed in Mombasa citing high cost when compared with the price at which they would pay in Nairobi.