The fourth person arrested by the police a week ago on suspicion of money laundering was Nexia BT partner Manuel Castagna, Times of Malta can reveal.

Castagna is Nexia BT’s partner responsible for audits and human resources as well as the firm's compliance principal.

Along with fellow partners Brian Tonna and Karl Cini and the former chief of staff at the office of the prime minister, Keith Schembri, all four are on police bail as the investigations continue.

Several sources confirmed the identity of the fourth person who Police Commissioner Angelo Gafà spoke about on Friday when he said four people had been arrested during the night between Monday and Tuesday.

Manuel Castagna.

Schembri, Tonna, Cini and Castagna were arrested on suspicion of money laundering after their assets were frozen by court order. They were released after interrogation.

Gafà said investigations had been going on for years and refuted claims that the arrests and the searches conducted by the police were too little too late. The arrests were made following a leaked secret court document so the police had to act fast, he added.

The document in question is an attachment order in which the court ordered the freezing of all assets of the companies and people mentioned in the order.

The list includes children, as young as just a few months.

Anyone convicted of money laundering could face up to 18 years in jail and a maximum fine of €2.5 million. A long list of other people mentioned in the court’s ‘attachment order’ could face the same punishment if convicted.

The arrests were made following a leaked secret court document

The order came a few days after it became known that a magisterial inquiry into claims that Schembri took a €100,000 kickback on passport sales from Tonna had been concluded.

The inquiry, conducted by Magistrate Natasha Galea Sciberras, was based on a leaked FIAU report that raised suspicions about two €50,000 transactions that passed between the pair via Pilatus Bank.

The inquiry had been requested by former Nationalist Party leader Simon Busuttil.

Conclusions of magisterial inquiries are secret and protected at law.

Schembri has claimed that the €100,000 payment, which originated from a company in the British Virgin Islands used by Tonna in connection with passport sales, was a loan repayment.

However, according to the FIAU, no trace of the original loan payment by Schembri to Tonna was ever found.

Philip Mercieca, a former Pilatus Bank director, had told the Egrant inquiry that the bank was “crazy” to have allowed the transactions between Schembri and Tonna to take place.

Schembri is also facing a separate inquiry into suspicions he filtered over €650,000 to ex-Allied Newspapers managing director Adrian Hillman in over 30 “suspicious transactions” between 2011 and 2015.