Two executives at the Saudi contracting giant MMG have been sentenced to five years in prison for breaching rules relating to accumulated losses, according to a Reuters report.

The local Capital Market Authority (CMA) Committee for the Resolution of Securities Disputes also fined Mohammed al-Mojil Group 1.6 billion riyals ($427 million), according to a representative for the family, the news agency said.

The men sentenced to jail were named as founder Mohammad Al-Mojil and his son Adel Al-Mojil, the firm’s chairman, Reuters said.

Shares in MMG have been suspended since July 2012. The Mojil family has denied wrongdoing and said they would appeal the decision, Reuters reported.

The investigative process was “defective from the start”, the family is reported as saying, with a “fundamental and deliberate lack of due process throughout”. The family alleges that the two executives were not given opportunity to respond to certain pieces of evidence used against them.

MMG services include construction, installation and turnaround services, according to its website. It started operating in Dammam in 1954.