The CIA and the Vatican have made alterations to Wikipeda entries, according to a US hacker's homemade program that detects the source of edits to the online encyclopedia.

Virgil Griffith's Wikiscanner points to Central Intelligence Agency computers as the sources of nearly 300 edits to subjects including Iran's president, the Argentine navy, and China's nuclear arsenal.

A CIA computer was the source of a whiny "Wahhhhh" inserted in a paragraph about Iranian President Mahmoud Ahmadinejad's plans for the office.

"While I cannot confirm whether any changes were made from CIA computers, the agency always expects its computer systems to be used responsibly," CIA spokesman George Little said in response to an AFP inquiry.

Wikipedia is a communally refined Internet encyclopedia that taps into the "wisdom of the masses" by letting anyone make changes.

Its founders believe people who know better will quickly correct inaccurate or misleading information.

Griffith, a university graduate student and self-described hacker, said his software matches unique "IP" addresses of computers with Wikipedia records, regarding which machines are used to make online edits.

"I came up with the idea when I heard about Congressmen getting caught for whitewashing their Wikipedia pages," Griffith explained on his Web site.

Most edits listed at Wikiscanner involve minor changes such as spelling. Some alterations involve removing unflattering information, adding facts or inserting insults.

Wikiscanner's roster indicates a Vatican computer was used to remove references to evidence linking Ireland's Sinn Fein leader Gerry Adams to a decades-old double murder.

Someone at the US Democratic Party's Congressional campaign committee changed a description of conservative radio talk show host Rush Limbaugh to replace "comedian" with "bigot" and dub his listeners "legally retarded".

"We don't condone these sorts of activities and we take every precaution to insure our network is used in a responsible manner," said committee spokesman Doug Thornell.

A Republican Party computer purportedly was used after the US invasion of Iraq to change "occupying forces" to "liberating forces" in a Baath Party entry.

A United Nations computer is identified as the source of an edit that calls a respected Italian journalist a promiscuous racist.

Someone using a US Senate computer altered a profile of veteran White House reporter Helen Thomas to complain she "interrupts" and is annoying.

An edit traced by Wikiscanner to the BBC changes causes of former prime minister Tony Blair's heart palpitations from strong coffee and vigorous gym workouts to vodka and exertion in a bedroom.

Wikiscanner also identified a BBC computer as being used to change US President George W Bush's middle name from "Walker" to "Wanker" at Wikipedia.

A computer belonging to Reuters news service is listed as adding "mass murderer" to a Wikipedia description of Bush.

Griffith said it appears common for political figures to "whitewash" entries by replacing negative adjectives with flattering ones and that corporations seem inclined to insert criticism of competitors.

Politicians and corporations show similar tendencies to remove critical information, according to Griffith.

Griffith still considers the collaborative open Wikipedia model reliable.

"Overall -- especially for non-controversial topics -- Wikipedia already works," Griffith says on his Web site.

"For controversial topics, Wikipedia can be made more reliable through techniques like this one ... to counteract vandalism and disinformation."