Investors in drinks giant PepsiCo have filed a shareholders resolution urging the company to account for alleged land-rights violations in Cambodia.

The 14 shareholders – including Oxfam – are increasing the pressure on PepsiCo following Coca-Cola’s pledge earlier this month of “zero tolerance” towards land grabs.

An Oxfam investigation last month found that PepsiCo, Coca-Cola, Associated British Foods (ABF) and their franchises have been linked to violent sugar-related land grabs in Cambodia. PepsiCo and ABF had yet to address the allegations made in Oxfam’s report Nothing Sweet About It, the charity said in a statement.

In the report, Oxfam cited a 2006 land-grab case in Sre Ambel district, Koh Kong province, where two companies belonging to Thailand’s Kon Kaen Sugar Co Ltd, which sells sugar to franchises that produce products for Coca-Cola and PepsiCo, were responsible for evicting 456 families from their land concession.

“The pressure is only increasing on PepsiCo to address the realities of its supply chain,” Judy Beals, manager for Oxfam’s Behind the Brands Campaign, said in the statement.

“The company is leaving itself open to immense risks if it fails to tackle land conflicts in areas where it sources ingredients. Coca-Cola has already identified these risks and made promises to address them. The question investors should ask is: Why is PepsiCo so far behind?”

PepsiCo did not immediately respond to requests for comment.

The resolution will be voted on at PepsiCo’s annual general meeting early next year.

“As shareholders we want to know what PepsiCo is doing to ensure its suppliers are behaving responsibly and preventing land conflicts from undermining its reputation and operations,” Beals added.

Complementing the resolution, more than 250,000 people have signed petitions supporting Oxfam’s campaign, which have been delivered to PepsiCo’s bottling plants in the US.

Cambodia’s sugar exports reached $13 million in 2011, with about 90 per cent of these exports going to the European Union under its Everything But Arms trade initiative, which allows duty-free imports from the world’s poorest countries.