A 'sunken' runway at Chengdu's airport resumed operations on Sunday following more than three weeks of repairs.

The sinking land - or subsidence - was suspected to be the result of poor construction, Times Weekly reported.

The second runway at Chengdu Shuangliu International Airport showed signs of land subsidence one year after being put into use, though that was not confirmed by the airport authority.

The alleged subsidence was first noticed by Ma Fan, a flight amateur who is interested in taking pictures of landing and taking off.

Ma's allegation later found support in a pilot's micro blog in which the airman complained about his bumpy experience when landing at the airport.

The report said the second runway was put into use in May 2011, nearly one and a half years after construction was completed.

The airport in Southwest China's Sichuan province is the fourth largest air hub in the country, which serves nearly 700 flights on a daily basis and 30 million passenger trips each year.