Man arrested and charged for alleged harassment of SA Speaker

South Australian Police have arrested and charged a man for alleged stalking and harassment.

The state’s lower house Speaker Nat Cook is understood to be the target of the alleged offending.

The man has been bailed and will appear in the Christies Beach Magistrates Court on December 7.

South Australian Police have arrested a man for alleged online harassment of a member of parliament, understood to be Speaker of the South Australian House of Assembly, Nat Cook.

In a statement, police said they attended a 33-year-old man's home in Reynella East on Friday, where he was arrested and charged with stalking and harassment.

They will allege the man breached a caution issued to him earlier this year by posting "numerous times on social media about the person".

He has been bailed to appear in Christies Beach Magistrates Court on December 7.

The man is understood to be Luke Poulton, a southern suburbs activist, who shared time-stamped CCTV footage of an arrest at his property to Facebook and Instagram pages he operates.

In his Facebook post, Mr Poulton was critical of the police's handling of his arrest and wrote the material prompting his arrest related to "3 facebook posts including a video montage showing people involved in bullying myself and my family".

He also wrote: "Australian Labor Party are really turning it on with the Helen Haines incident," referring to the recent attack on the federal Indi MP in Wangaratta.

Mr Poulton declined to respond to a request for comment, or permit ABC News to share the footage of his arrest.