Malaysia's former finance minister Lim Guan Eng is filing a defamation suit against an Umno Youth leader over a false story alleging his son was arrested in Singapore.

In a statement issued on Sunday Lim, who is also secretary-general of the Democratic Action Party (DAP), said his family is “furious” over the claim, which was also published by Chinese daily Nanyang Siang Pau without the facts being verified.

“My family is furious for such shameless targeting of our innocent children, who are not in politics,” said Lim.

He said the false accusation was also repeated by political parties Umno, Parti Islam SeMalaysia (PAS), and supporters of the Umno-led Barisan Nasional (BN) coalition.

“A national Umno Youth leader using the name ‘Papa Azri’ had started off this malicious lie by stating that I flew to Singapore on February 29, after my son was hauled up at Singapore Airport for bringing in RM2 million ($467,450) in cash without proper declaration,” he added. “This news then went viral through the BN and Umno support groups, especially their internet websites”.

Papa Azri is a moniker used by Umno Youth leader Wan Muhammad Azri.

Rumours of 28-year-old Clint Lim’s arrest in Singapore went viral on Saturday on social media, and was later written up by pro-Umno blogger Raja Petra Kamaruddin in the Malaysia Today site.

Nanyang issued a statement on Sunday apologising to the affected person in the article as well as to its readers. It had identified the affected person only as the son of a senior Pakatan Harapan (PH) leader, but not named Lim or the DAP, which is part of the PH pact.

“Upon checks, the report was based on incorrect information,” the Chinese daily said.

This is not the first time Lim’s children have been the subject of false reports.

In 2011, various blogs uploaded a post alleging that another son, Marcus, had molested a classmate. The claim was later proved to be false after the purported victim, a chess champion from Hong Kong, said she had never met him. Her photo on the blogsites was found to have been taken from a chess tournament she participated in.

On Saturday, national police chief Hamid Bador confirmed that allegations of Clint’s arrest were unfounded.

“It is definitely not true . . . We have not gotten any report that his [Lim’s] son was detained in Singapore,” Tan Sri Hamid said.

“This is definitely fake news being spread,” he told The Star daily. He also denied that Clint is being investigated by police.

Hamid said police will instead investigate perpetrators behind the misinformation.

Lim said he expected to be attacked by his political opponents with threats and falsehoods. But he lashed out at attacks against his family, saying: “My political opponents who are now in power, have shown themselves without any shame, bereft of moral or humane values and upbringing by mercilessly targeting my innocent children.”

Former ruling pact PH, which now comprises DAP, Parti Keadilan Rakyat and Parti Amanah Negara, was ousted from power in February after Parti Pribumi Bersatu Malaysia exited the pact and left it without a majority in Parliament.

The new government, Perikatan Nasional, comprises a loose partnership between Bersatu, Umno, PAS and Gabungan Parti Sarawak.