A man will face a Sydney court next month, accused of sending harassing letters to the families of Australian soldiers killed in Afghanistan.

The 45-year-old from Croydon Park, in the city's inner west, was charged yesterday after an investigation by the Sydney Joint Counter Terrorism team.

Officers from that team carried out searches at his home and two other homes in Campsie and Green Valley.

Police believe the man sent seven harrassing letters.

He has been charged with using a postal service to menace and cause offence.

Federal police released the man on bail until his first court appearance in the Downing Centre Local Court next month.

The offence carries a maximum penalty of two years in jail.