The father and uncle of a notorious fighter who fled Australia to join the Isis terror group have been jailed after pleading guilty to bribery charges.

The pair, Mamdouh Elomar, 63, his brother Ibrahim Elomar, 61 – along with businessman John Jousif, 48 – were sentenced to at least two years in jail as they conspired to pay a $1m (£746,658) bribe to a foreign public official in order to gain contract work in Iraq in 2015.

Justice Christine Adamson at the New South Wales (NSW) Supreme Court sentenced the three men to four years in jail with a non-parole period of two years, on Wednesday (27 September). They two brothers were also fined $250,000 each, AP reported.

The brothers were facing financial hardship as their company Lifese – involved in engineering, infrastructure and construction projects – was losing deals after publicity on Mohamed Elomar's decision to join Isis became public as well as one of his brothers' conviction for terror-related offences.

Elomar is believed to have been killed as he fought with Isis in Iraq in 2015. His brother, Ahmed, was released on parole last year. He was sentenced for attacking a police officer with a pole during a violent protest in Hyde Park in 2012.

Jousif first approached the two brothers in 2013. They initially explored business opportunities in Iraq in a lawful way.

However, when Jousif told them they would be blacklisted if payment was not made, they conspired to provide a benefit to another person in order to influence a foreign public official and obtain business.

The conspiracy ran between July 2014 and February 2015. The brothers gave more than a $1m in cash to Jousif, who transferred the money to a man in Iraq through a money exchange business in Auburn, western Sydney.

The two brothers, however, were never awarded contracts for work in Iraq. There is no evidence on where the money ended, after it was transferred to Iraq.

While delivering the verdict, the judge said Jousif was the "middleman, conduit and facilitator" who encouraged the brothers to set up business in Iraq.

He described the two brothers as seasoned and successful businessmen whose greed "was exploited". However, he rejected a a contention that the brothers were coerced into paying.