Police were called to a security alert at Sinn Fein MLA Pat Sheehan's office in Belfast on Friday night.
Police were called to Mr Sheehan's office on the Springfield Road after receiving a call that suggested a suspicious object may have been left outside the premises.
Nothing was found during the search and police are treating the incident as a hoax.
The incident ended at around 1.30am.
Sinn Fein has been approached for comment