Tas man swept down river, body found

A Tasmanian man has died after he was swept downriver on a frigid night in the state's northeast.

The alarm was raised about 8pm on Sunday when the 67-year-old man was seen in the Ringarooma River in Derby.

Sergeant Scott McKinnell said police search and rescue teams and State Emergency Service volunteers searched for the local man into the night.

"The temperature in Derby was around zero at the time the man went missing, with heavy fog, which made conditions very tough," Sgt McKinnell said in a statement.

SES volunteers found his body about 1.30am, 400m downstream from where he was last seen.

A report is to be made to the coroner.