One of Israel’s largest public construction companies is suspected of laundering NIS 60 million ($17.3 million), tax fraud, and funding the criminal activities of the country’s most active organized crime ring, police said Tuesday.

Four suspects, two of whom are the founder and CEO of the contracting company, were arrested on Monday.

On Tuesday, a Rishon Lezion court extended the remand of the suspects until May 26, and the crime lord implicated in the affair — who is currently in prison — was brought to the hearing and is considered the prime suspect in the case.

The police probe, which is ongoing, purportedly shows ties between mob boss Yitzhak Abergil and the administration at the unnamed building company. Police maintain the company and Abergil orchestrated the scheme both while the latter was abroad, and while while he was in prison.

The homes of the suspects were ransacked by police, and computers and documents seized for the purpose of the investigation. More arrests are expected to be made.

Probes were begun in 2011 simultaneously by the Tax Authority and police, with regard to questionable financial discrepancies in an unsuccessful building project by the company in Eilat in 2007. The case was ultimately dropped, but was later reopened when new information emerged. The police’s Unit of International Crime Investigations, along with the Tax Authority and the Money Laundering and Terror Financing Prohibition Authority, were involved in the investigation.

While a gag order has been imposed on the name of the company and the names of two of the suspects, police cleared the names of Shimon Belulo of S.I.N. GAN RAVE LTD, and Nisim Pines, Globes reported.

The company’s attorney, Ruth David-Blum, denied the charges in Tuesday’s hearing.

“To say that this company can, or is able to, conceal 60 million shekels is impossible,” she said. According to David-Blum, the company makes NIS 3 million-NIS 4 million a year, and all its financial affairs go through the banking system.

Abergil and his brother Meir were arrested in August 2008 in Israel following an American extradition request, after they were named in an indictment that charged them with using a San Fernando Valley gang to distribute one million MDMA pills, colloquially known as ecstasy, and paying a gang member to kill a man for stealing a drug shipment. Abergil was handed over to US officials in January 2011.

In May 2012, Abergil pleaded guilty to the charges as part of a plea agreement, and was sentenced to 8.5 years in prison, of which he has already served over five (including time spent in prison prior to sentencing). His brother Meir was sentenced to 42 months and has since been released.

Abergil landed in Israel on January 30 after three years in a US prison, and will spend the remainder of his sentence in an Israeli prison.

Itamar Sharon contributed to this report.