Three former lawyers and two other men who were involved in a £1.48 million money laundering operation have been jailed.

Iain Robertson, Alastair Blackwood and David Lyons, who were solicitors, and Mohammed Aziz and Robert Ferguson were found guilty of multiple charges under the Proceeds of Crime Act following a trial at the High Court in Glasgow.

Lyons, Robertson, and Aziz were also convicted of being involved in serious organised crime.

Robertson, 69, of Kilmacolm, Inverclyde, was jailed for eight years while Blackwood, 68, of Dunlop in East Ayrshire, and Lyons, 71, also of Kilmacolm, were each jailed for seven years when they returned to the court on Wednesday for sentencing, the Crown Office said.

Aziz, 61, from Glasgow, was sentenced to seven years behind bars and Ferguson, 67, of Thornliebank, East Renfrewshire, was jailed for 16 months.

The court proceedings were triggered by a Law Society investigation into the Paisley legal firm Robertson & Ross after concerns were raised about some transactions.

Laura Buchan, Crown Office and Procurator Fiscal Service (COPFS) procurator for specialist casework, welcomed the sentences.

She said: “The public rightly must have confidence in lawyers to uphold the law. These individuals fell far short of the standards of professional conduct the public are entitled to expect from members of the legal profession.

“Money laundering is not a victimless crime and plays an integral role in a complex, large-scale operation which facilitates the criminal activity of others.

“I hope these convictions and the sentence send a strong message to others involved in this kind of criminal behaviour and demonstrates the ability of police and prosecutors to investigate, prepare and prosecute serious and organised crime of this nature.”

Prosecutors said the case centred on four transactions carried out between May 2015 and July 2016.

The first transaction involved a £79,340 stolen cheque due to be paid to a law firm in Jersey, while the next centred on £240,000 from a fraudulent house sale in London.

The third transaction saw £985,000 stolen from the hacked bank account of an individual, and the final activity was uncovered after Robertson claimed to be acting for a man who wanted to sell his home in Essex.

The court heard the “seller” was said to be staying at a flat that turned out to be Ferguson’s address. A total of £181,786 was made from the fraudulent sale.

In each transaction, the proceeds were funnelled through the client bank account held by Robertson’s firm in Paisley – Robertson & Ross Limited – and false records were created to make them appear legitimate.

The Crown Office said the trial heard Robertson was at the heart of the money laundering scheme since he had access to his firm’s client account.

All five men had pleaded not guilty to the charges.

David Gordon, convener of the Law Society of Scotland regulatory committee, said: “The Law Society has robust anti-money laundering measures in place to protect the public and ensure the legitimate services provided by legal practices are not misused for criminal purposes.

“This outcome in court highlights the importance of taking swift action and ensuring that concerns were reported to the authorities.”

Police Scotland Detective Superintendent Dave Ferry said: “Targeting the movement of criminal cash and profits in Scotland remains a priority.

“This was a complex investigation which involved a number of partner agencies to trace the movement of money, which ended up being channelled through the law firm’s accounts.

“I welcome their conviction and the fact that a significant amount of money has been identified and taken out of criminal circulation.