British homewares retailer Habitat apologized on Wednesday after ads for the store appeared on Twitter tagged with words linked to the Iranian election crisis.
Some Twitter users became angry after the upmarket store's messages turned up in searches for topics such as "Iran" and "Mousavi," the name of Iranian presidential candidate Mir Hossein Mousavi.
Tags with those terms had been attached to the store's messages on the micro-blogging site.
Habitat said in a statement that it "would like to make a very sincere apology to any users who were offended by last week's activity on Twitter."
The posts — some of which featured other popular topics such as "iPhone" — have been removed.
Hashtags — words or phrases prefixed with the number symbol — are used on Twitter to help direct users to tweets about specific topics.
Habitat said Twitter's top "trending topics," or popular subjects, had been pasted into its messages without the company's consent. It would not say who was responsible.
"This was absolutely not authorized by Habitat," the company said. "We were shocked when we discovered what happened and are very sorry for the offense that has been caused.
"This was totally against our communications strategy. We never sought to abuse Twitter, have removed the content and will ensure this does not happen again."
Twitter has been widely used by people inside and outside Iran to track events in the crisis over the Islamic Republic's disputed presidential election.