Malta Minister Justyne Caruana has to resign just a week after being sworn in as her husband was suspected of being involved in a journalist murder.

"I decided to leave my post, even though it was completely unrelated to this issue," Gozo Island Secretary Justyne Caruana wrote in his resignation to Malta Prime Minister Robert Abela today.

The decision was made just a week after the new Malta cabinet was sworn in. State media reported yesterday that Silvio Valletta, a former police officer and the minister of Caruana's husband, was involved in the British billionaire Yorgen Fenech, who was accused of masterminding the murder of journalist Daphne Caruana Galizia.

She held the position under former Prime Minister Joseph Muscat, who also resigned for allegedly obstructing the investigation of the case.

Valletta was deputy Malta police chief when journalist Galizia was assassinated by car bombs for exposing a series of corruption cases in the cabinet of government. He withdrew from the investigation in June 2018 after the court concluded that Valletta had a conflict of interest with the victim's family.

Valletta admitted to following a football match in England with Fenech in September 2018, but confirmed that the incident happened after he withdrew from the case and did not know that the British billionaire was under investigation. "I have done nothing wrong and certainly will not go abroad with people suspected to be involved," he added.