Annie Leibovitz, seen here with her portrait of Queen Elizabeth II in 2007, is being sued for breach of contract by lender Art Capital. ((Jacquelyn Martin/Associated Press))

Celebrity photographer Annie Leibovitz "is continuing to work to resolve" her dispute with New York lending company Art Capital Group, her spokesman said on Wednesday.

On Tuesday night, the deadline passed for the famed photographer to repay a $24-million US loan to the lender, which launched a breach-of-contract lawsuit against Leibovitz in July.

In 2008, Leibovitz put up as collateral her four New York properties and the copyright to every picture she has ever made in exchange for a loan from Art Capital, which specializes in lending with fine art as collateral.

According to the lawsuit, the photographer, 59, has since refused to allow appraisers to value her homes and refused to meet with parties interested in buying her photo collection.

Leibovitz is renowned for capturing iconic portraits of famous people, from Demi Moore to John Lennon to Queen Elizabeth II.

With files from The Associated Press