The singer was pictured yesterday (January 2) with bruises and a bandage on her hand after an alleged physical conflict with Theo de Vries during a skiing trip to Austria.
However, de Vries has since shown off injuries apparently inflicted by Harding in the clash, including a bite mark on his leg that required him to have an injection and a bruised eye caused by a thrown ashtray.
"She gave me a bloody nose. Don't forget that she is a very good kick-boxer," he told The Sun. "I want everyone to know that I am a normal decent man. I didn't hit Sarah one time."
Asked about Harding's bandaged hand, de Vries stated that there was "zero per cent truth" to suggestions that he caused the injury.
"I really had to laugh at that picture," he said. "Sarah is an actress and don't forget it."
Meanwhile, a friend of Harding dismissed the "ludicrous" version of events relayed by de Vries.
"[Sarah] believes she was clearly defending herself," they told The Mirror. "He'd been drinking while she was sober and decided to end it. He didn't take it too well and got in a fight in which he hit her."
A police spokesperson in Austria confirmed yesterday that de Vries had been questioned and released, prompting the launch of a report to decide if assault charges will be filed.
Asked about the incident during an appearance on Lorraine this morning (January 3), Harding's Girls Aloud bandmate Nicola Roberts said only: "I've spoken to her and she's home now. She's fine."
Harding recently completed a rehab stint for alcohol and depression issues sparked by her split from fiancé Tom Crane.