The deputy leader of an up-and-coming political party contesting Thailand’s general election has become the latest target of heavily restrictive online content laws after unwittingly sharing a false news article.

A spokeswoman for the Future Forward party said on Tuesday that a representative of the ruling military junta had filed a police complaint accusing Pongsakorn Rodchompoo of violating the Computer Crime Act, which carries a penalty of up to five years in jail.

Pongsakorn has admitted sharing an article that accused a top junta official of buying cups of coffee for 12,000 baht ($377) each, but says he deleted the post within minutes after learning it originated from a website promoting fake news, Future Forward spokeswoman Pannika Wanich said. The story had been widely circulated on Facebook. Five other people have reportedly been charged for the same offence, accused of violating a provision of the law against online activity that endangers national security.

Prayuth Chan-ocha, the prime minister and head of the military government, is seeking to stay in office after the 24 March election. He is the nominee for prime minister from a new party that is regarded as a proxy for the military. He is not running for parliament – laws passed under the junta’s rule allow so-called outsider, or unelected, prime ministers.

The junta has already filed charges against Future Forward party leader Thanathorn Juangroongruangkit for online remarks it says unfairly lured other political parties to be its allies. He is accused of violating the Computer Crime Act by allegedly putting false information online.

Thanathorn is a particularly articulate critic of Prayuth and the military and his case will not be considered until after the election.

In another case Thailand’s army chief, General Apirat Kongsompong, has ordered officials to file defamation charges against a former police chief who is running for prime minister after he made remarks regarding the many decorations on the general’s uniform, Thai media reported on Tuesday.

Thailand’s Election Commission, which is nominally independent but generally follows the direction of the government, also has oversight over online election material. On Monday it ordered 12 social media postings be deleted for false or offensive messages.

The commission is also looking into a complaint that Future Forward posted a false detail on its website about party leader Thanathorn’s career, an infraction punishable by a fine, imprisonment and a ban from politics for up to 20 years. The incorrect entry described him as the head of a national industrial organisation rather than of one of its regional branches. His party said it was a clerical error.