Armed officers and the police helicopter were called to St Leonards after reports of a man with a handgun.
Shortly after 9.30pm on Thursday (October 17) police were called to a property in Church Road, St Leonards.
At 5.42pm on Friday (October 18), a police spokesman confirmed what officers were called to – reports that a man had been seen with a handgun.
Armed officers attended and the weapon was seized. It was later identified as a ball-bearing gun, police said.
A National Police Air Service helicopter also assisted during the incident.
Nearby roads were temporarily closed for public safety while the incident was dealt with.
Police said nobody was hurt.
A spokesman for Sussex Police said a 30-year-old man has been arrested on suspicion of possessing a firearm with intent to cause fear of violence.