By Courtney Sherwood

PORTLAND Ore. (Reuters) - An Oregon man has sued Costco for $670,000, claiming store security detained him and broke his leg after he refused to show his receipt when exiting the building.

Timothy Walls says in his Multnomah County Circuit Court lawsuit, which was filed last week, that when he tried to leave a Portland Costco store with $102.66 in purchases in January last year, an employee grabbed his shopping cart and told him to present his receipt for inspection.

When Walls refused, another Costco employee used a “martial arts type strike” that fractured his leg in multiple locations, according to his civil complaint.

Walls’s attorney said Tuesday that the litigation is about much more than the broken leg.

“We have, throughout the country, observed big box stores that have implemented policies to check all receipts at the door,” lawyer Clayton Morrison said. “They can have that policy. But if the person refuses to show their receipt, what is lawful for the store? Can they detain you?”

Costco could have prohibited Wells from returning to the store, but forcing him to stay with no reason to suspect him of a crime amounted to “unlawful holding,” Morrison said.

Costco’s lawyers have declined to discuss the case with the media, but in court filings they said that Walls attacked first.

The members-only warehouse box store in its court filings said that Walls refused to show his receipt, then threw an employee against a wall and struck him in the throat after the worker called for a manager to resolve the dispute.

Walls’s injuries were “the sole and direct cause of Plaintiff’s own actions,” Costco said in the court papers.

Walls is asking for $500,000 for pain and suffering, $150,000 for medical expenses and $20,000 for lost wages, and has requested a jury trial. A trial date has not yet been set.

(Reporting by Courtney Sherwood in Portland, Oregon; Editing by Dan Whitcomb in Los Angeles)