More than 43 percent of Chinese farmers in a wide-ranging study have been victims of land grabs and local governments have made huge profits in the process, state press said Tuesday.

Land grabs have become an explosive issue in China as officials seeking to cash in on a property boom increasingly force farmers off their land to make way for construction -- an issue repeatedly condemned by Premier Wen Jiabao.

In one recent protest, villagers in the wealthy southern province of Guangdong faced off with authorities for more than a week in a row over land and graft, eventually winning rare concessions.

According to the study, conducted in 17 provinces and regions by Beijing's Renmin University and published in the 21st Century Business Herald, nearly a quarter of farmers did not receive any compensation for their land.

Almost two thirds of those surveyed who did receive compensation got a lump sum, which averaged 18,739 yuan ($3,000) per mu, a Chinese unit of land equivalent to 0.16 acres or 0.07 hectares, according to the study.

This compares to an average land sale price of 778,000 yuan per mu for local governments -- or more than 40 times the average compensation sum given to farmers. The others received their money in installments.

On a visit to the southern manufacturing hub of Guangdong over the weekend, Wen reiterated his concern over land grabs.

"Unauthorized expropriation of farmland has been a common problem, causing many complaints and even mass disturbances," he was quoted as saying by the official Xinhua news agency.

He added that farmers' land "has not been fully protected".

Officially, Chinese farmers are not owners of the land they cultivate, but since decollectivisation more than 30 years ago, they have the right to use plots through long-term leases.