Someone working in the 950 strong department has been getting into the Wikipedia profile on Senator Wong, Labor's leader in the upper house of federal Parliament, and deleting references to her two children.

Senator Wong was a leading figure in the push for same-sex marriage who has been outspoken against attacks on children of same-sex couples as a "stolen generation."

The anonymous public servant behind the trolling could be in hot water, if caught, with the department saying its employee's online activities could put them in breach of the Victorian Public Sector Code of Conduct.

Changes were made to the site's page about Senator Wong on several occasions in recent months from up to six different computers, removing references to her children or simply referring to them as the children of the politician's partner Sophie Allouach.

The changes were quickly corrected by accredited Wikipedia editors.

The online encyclopaedia can be edited by anyone, but inaccurate, mischievous or malicious material is usually removed or corrected quickly by the site's accredited editors.

One of the computers used in the trolling had an IP address in the premier's department.

The South Australian senator, who is very protective of her family, declined to comment on Wednesday.

A spokesperson for the department told online news service Buzzfeed that an internal investigation had commenced.

"These edits are not endorsed by the Department of Premier and Cabinet," a spokesperson said.

"The department has an internet use policy for staff that allows for reasonable personal use (not illegal, interfere with work productivity, excessive downloads etc).

"While the examples provided do not breach the reasonable use policy, they may be in breach of the Victorian Public Sector Code of Conduct."