Business Insider reports the US's largest mall operator filed a lawsuit against Gap Inc. on Tuesday.
The suit alleges that Gap has not paid more than $65.9 million in rent and other charges over the past three months.
"The amounts due will continue to accrue each month, with interest."
Simon Property Group is among the landlords in the US to have been squeezed by the pandemic.
Many retailers have refused to pay rent as stores remained closed.