A British lawyer has asked the International Criminal Court to investigate “widespread and systematic” land grabbing in Cambodia over the past 14 years as a crime against humanity.

The complaint filed in The Hague yesterday by lawyer Richard Rogers, who is officially representing 10 Cambodian victims, alleges that a “ruling elite” has perpetuated mass rights violations in pursuit of wealth and power.

“The communication contends that senior members of the Cambodian government, its security forces, and government-connected business leaders carried out an attack on the civilian population with the twin objectives of self-enrichment and preservation of power at all costs,” says a statement released by Global Diligence LLP – where Rogers is a partner – and the International Federation for Human Rights.

Rogers says that crimes committed by the elite group in pursuit of these goals “include murder, forcible transfer of populations, illegal imprisonment, persecution and other inhumane acts”.

While specific individuals are not identified, the complaint recommends the court prosecutor look at the role of specific police and military units involved in evictions. “Deportation or forcible transfer of populations” falls under the court’s definition of crimes against humanity.

Rogers’s evidence estimates that some 770,000 people – or 6 per cent of the population – have been negatively affected by land grabbing in the Kingdom since 2000, with more than 145,000 forcibly relocated from Phnom Penh.

A summary of the complaint says that the ruling elite accomplished this by exploiting land tenure insecurity in post-war Cambodia (the Khmer Rouge abolished land titles) and using a malleable judiciary and state security forces to help them.

It also says that violence has long been used to protect the interests of this elite group from dissidents, including activists, lawyers, journalists, unionists and opposition members.

In sum, the alleged crimes represent a “widespread and systematic attack against the civilian population” and are “pursuant to state policy”, according to the complaint.

The ICC has received at least two other “communications” related to Cambodia since 2012, but Rogers – who previously served as head of the Defence Support Section at the Khmer Rouge tribunal – has high expectations.

“I am confident that the ICC will initiate a preliminary examination. The law on this is very clear. The definition of crimes against humanity does not require an armed conflict,” he said in an email.

A decision to launch a preliminary investigation could be made in the next six months, but would then likely take years, and there would be no guarantee of either a formal investigation or trial.

“The question for the ICC is, at what point do these types of human rights violations become so grave that (when taken together) they amount to an international crime and meet the gravity threshold? Do we wait until 5 per cent of the population has been affected, or 10 per cent?” Rogers said.

Government spokesman Phay Siphan, who had previously mocked the lawyer’s efforts, said yesterday that the complaint was “still a joke”, and was not only exaggerated, but politically motivated.

“It’s polarised by politics. We might know who sponsors or who pays money for him and who belongs to whom. I understand [opposition deputy leader] Kem Sokha’s daughter is also involved in the complaint.… It was [started] during the [post-election] campaign and related to the political deadlock,” he said.

Following the fatal shooting of at least five garment workers by authorities in January during violent protests, the opposition Cambodia National Rescue Party announced it had engaged Rogers to investigate crimes committed by state security forces against civilians for a possible ICC complaint.

But Rogers says that when he met victims and victims groups, they asked him to consider a “much broader range of crimes”. Although Rogers is the CNRP’s international counsel, the complaint has been filed on behalf of those victims, not the political party.

Kem Monovithya, a daughter of Sokha who is CNRP deputy public affairs head, said that while her name was on the original press release, she played no role beyond “connecting” Rogers to the alleged victims.

CNRP spokesman Yim Sovann also denied the complaint was politically linked.

“Because Cambodian courts have proved unwilling and unable to deal fairly with human rights violations raised in the ICC complaint, we support the request for an investigation by the ICC prosecutor,” he said.