Actor Jeremy Renner, who plays Marvel's eagle-eyed hero, has shut down his app after it was hijacked and used to harass people.

Abuse and harassment mushroomed after trolls found a way to impersonate the actor and others on the Jeremy Renner Official app.

Renner apologised for the shutdown in a post explaining what had happened.

Identity crisis

Created in 2017, the app, on which Renner regularly posted exclusive images and content and occasionally messaged users, also operated as a community hub where fans could post their own stories and communicate with each other.

In his explanatory post, Renner blamed "clever individuals" who had found a way to pose as other users.

The problem appears to have emerged because the app had no way to verify the identity of people who downloaded it, which meant tech-savvy trolls could pose as regular users.

The app was shut down soon after Renner posted his message.

In his apology, he said anyone who had bought some of the app's own-brand currency in the past 90 days would be refunded.

"What was supposed to be a place for fans to connect with each other has turned into a place that is everything I detest and can't or won't condone," he said.

"My sincere apologies for this to have not turned out the way it was intended."