An American secret service officer has been arrested after he was found passed out on a Miami street corner less than 12 hours after President Barack Obama had left the city.

US secret service officers are uniformed members of the agency, and perform support services, in contrast to plain-clothed agents who directly guard the president and vice president.

The incident is being turned over the Secret Service's Office of Professional Responsibility, its internal affairs unit.

This is another scandal for the agency which was embarrassed by a prostitution scandal last April.

A dozen secret service employees were accused of misconduct for bringing women, some of them prostitutes, to their hotel rooms in Colombia in April ahead of Obama's visit to Cartagena.

A US government investigation concluded their actions did not compromise the president's safety, but the event was an embarrassment for the Secret Service and its director issued a stricter code of conduct afterwards.

Elsewhere, a shot was fired through the window of US President Barack Obama's Denver campaign office yesterday afternoon.

According to a spokeswoman, people were inside the office when the shooting happened, but no one was hurt.

A large panel of glass was shattered during the incident.

Police said investigators were looking at surveillance video but have not yet confirmed a description of a vehicle that might be linked to the shooting.

There had not been any previous threats against the campaign office.