Gundam is a popular animated science-fiction series

One man was found to have made 260 entries to articles about Gundam, a popular animated series featuring giant robotic fighting machines.

Five more bureaucrats wrote about Japanese movies, mistakes on billboards and local politics, officials said.

According to the ministry, the six had made 408 entries at work since 2003.

The group, whose activities were discovered by an internal probe, received verbal reprimands, officials said.

Editing Wikipedia has now been banned at the ministry.

"The Agriculture Ministry is not in charge of Gundam," ministry official Tsutomu Shimomura told the Associated Press news agency.

Wikipedia is an online encyclopaedia that anyone can add to.

A new website has now made it possible to track those who edit the site.