South Sudan is planning to crack down on an army of "ghost workers" soaking up millions of dollars desperately needed for development, a senior official said on Wednesday.

Corrupt officials have been adding the names of relatives to swollen payrolls and collecting their salaries, said Albino Mior Aguer, director general of establishment and budget at the southern Ministry of Labour and Public Service.

"A person could put all of his children's names down ... Millions and millions of pounds are wasted," he said.

Aguer said his office was planning to organise headcounts in 10 southern regions to cut back on the graft but it was impossible to say how many ghosts were in the system.

A headcount in central ministries had already recovered a month's worth of misdirected salaries totaling $250,000, he said. Checks on regions had also found payroll records for up to 100 workers where only about 20 were actually on the premises.

"Most of the states spend their money on salaries. it leads to redundancy at work, no services and no development," Aguer said.

Leonard Logo Mulukwat, head of finance for the Central Equatoria region, said one third of the state assembly payroll there had been going to people who were not working.

Mulukwat said he had since crossed out the ghost names and started an investigation into who put them there.

Southern officials say many of the names were inherited from the region's civil service system run by north during the country's ruinous north-south civil war.

Semi-autonomous Southern Sudan reached a power- and wealth- sharing deal with the north in a 2005 peace deal that ended the 21-year conflict.