The younger sister of a former labour union leader was on Thursday sentenced to six months in prison for perverting the course of justice by taking away the latter’s electronic devices upon learning of her arrest.

Earlier this month, Marilyn Tang, 63, admitted to West Kowloon Court that she removed possessions from her sister Elizabeth’s flat in Mei Foo.

Elizabeth Tang, the former chief executive of the now-disbanded Confederation of Trade Unions and the wife of jailed former lawmaker Lee Cheuk-yan, was arrested by national security police for suspected collusion with foreign forces in March this year.

The court had heard that on March 9, Marilyn went to the flat twice before police officers arrived to seize evidence. Police arrested her two days later and found a mobile phone and laptop that belonged to her sister.

In sentencing, magistrate Patrick Tsang said there was no evidence showing that Marilyn had turned on, interfered with or damaged the electronic devices, which did not contain any criminal information.

The judge also said the act of taking away the devices did not have an impact on Elizabeth’s alleged offence.

Noting Marilyn's clean record and her active participation in community work, the magistrate took a starting point of nine months in prison and reduced it to half a year, given her guilty plea.