Prosecutors in Taiwan have detained the head of a local administrative body in a case where dozens of officials are believed to have been entertained by Chinese authorities, with Taiwan's presidential election a month away.

Taiwan Keelung District Persecutors Office found more than 30 people, including heads of local communities in Keelung city, traveled to Shandong Province in China in November. Almost all expenses for the trip were reportedly paid by people in China.

Sources say that at a reception Chinese officials called Taiwan's largest opposition party, the Kuomintang, their family and asked Taiwanese attendees to support the party, not the ruling Democratic Progressive Party.

The prosecutors detained one of the heads on Thursday for violating Taiwan's election law, as the official is suspected of organizing the trip at the request of Chinese authorities.

It has emerged that the heads of local communities across Taiwan have been entertained in China. The government of the Democratic Progressive Party believes Chinese authorities aim to influence voters in Taiwan by winning over those officials.

Taiwan's Central Election Commission published the list of presidential election candidates on Friday, with official campaigning set to begin the next day.

A senior commission official warned voters to watch out for incorrect or fake information about the election posted online.