The number of emailed tips to the Justice Ministry’s Immigration Bureau about non-Japanese illegally staying in the country has more than tripled since May, the Asahi Shimbun said on Wednesday.

The bureau believes the tips were prompted by rumors over the Internet that ethnic Korean residents were to be deported, and suspended the online tipping system in order to consult with the police.

The number of emails it received on the homepage was around 460 every month on average last year, but it surged to 1,821 in May and 1,562 in June. The number rose further between July and September. “It is possible that the number could exceed 10,000 for the three months,” the newspaper quoted an official of the bureau as saying. The official said the number of groundless tips about ethnic Koreans increased.

Earlier this year, rumors began circulating that ethnic Koreans will become illegal residents after July 9 and be subject to deportation. Some Internet entries said: “Let’s give tips about Koreans and get awards.”

Worried about the effect the large number of emails may have on the computer server, the Immigration Bureau stopped receiving emails at the end of October. There were also indications the same person sent a massive number of emails. The bureau will resume accepting tips after taking steps to get rid of such emails.

The bureau also consulted with the police in November to check if it could bring criminal charges over the emails.

“Emails to defame non-Japanese is not the purpose of the tip system, and it is extremely sad,” the newspaper quoted the official as saying.