Ikea spokeswoman Tina Kardum said the product had only been on sale for a month when it was pulled off the shelves on March 22.
The company didn't announce the withdrawal publicly until Swedish newspaper Svenska Dagbladet wrote about it Saturday.
Kardum said the company found out Friday that a follow-up test in Belgium confirmed the lasagna contained 1.6 percent pork.
"We have more information now. That's why we choose to inform now," Kardum said.
Moose meat is common in Sweden though it's not typically used in lasagna.
Ikea has previously recalled meatballs and other meat products sold in its cafeterias and frozen foods sections after tests showed they contained traces of horsemeat.
The Swedish furniture giant is one of many European companies caught up in a scandal over mislabeled meat in frozen food products.
Ikea's withdrawn products came from a Swedish frozen foods maker, which in turn blamed the mislabeling on its meat suppliers.