Despite this shortfall, city mayor Amos Masondo led a 16-member delegation on a costly 10-day trip to four countries last month as part of a "study tour" aimed at bolstering "service delivery".
Johannesburg has also come under fire for spending R45-million to host the Miss World pageant for the second year running, amid accusations that the city is cash-strapped.
In a written response to questions by DA councillor John Mendelsohn, the finance chief of the mayoral committee, Parks Tau, said 323074 unpaid municipal accounts from 2008-2009, totalling R2.8-billion, had been written off.
This shocking figure is revealed when the city's finances are under severe strain, and after Finance Minister Pravin Gordhan ordered provincial and local governments to tighten their belts and slash unnecessary expenses.
The Times has established that, between November 7 and 17, Masondo took members of his mayoral committee and executive team, including three aides, to Mumbai, in India, Ho Chi Minh City, in Vietnam, Shanghai, in China, and Saint Petersburg, in Russia.
His spokeswoman, Nkhensani Makhobela, confirmed that the trip "wasn't a sponsored one but a study tour", meaning ratepayers paid for it.
She promised to give more information about the cost of the trip but did not; neither had she responded to detailed questions from The Times at the time of going to print.
Last night, the city's communications chief, Gabu Tugwana, said he was also unable to give further details, including the cost of the trip.
An earlier press release from the city said the trip was intended to "share experience and expertise in the hope of securing good relations among the cities".
"The city is committed to improving its performance by building international relations in order to learn and possibly adapt what other cities in the world are doing in similar areas of service delivery," the press release said.
It is understood that the trip is one of many taken by several members of the mayoral committee in the past six months.
The Times recently reported that Johannesburg had cut its operating budget by R1.1-billion to fund the completion of Soccer City stadium because of cost overruns. Our report also revealed that the city was struggling to pay some of its suppliers, forcing some to close shop.
Referring to the massive debt write-off, another city spokesman, Virgil James, said it ''is not abnormal".
"The city is neither cash-strapped nor in debt," he said.
"[Writing off of debt] is part of cleaning the books. All necessary channels to recover the money were exhausted."
But economists said the R2.8-billion write-off was highly irregular and could put the city in financial distress.
T-Sec economist Mike Schussler said: "That is quite a huge chunk [of the budget that] we can't afford to write off."
"You can't write off more than 10% of your budget in one go. It is a very, very big amount."
"Should power utility Eskom succeed in securing its 35% tariff increase in each of the next three years, all cities can expect a huge spike in electricity account defaults, which will probably lead to more write-offs," Schussler said.
According to a report in possession of The Times, until June the city's departments, plus PikitUp, Joburg Water, City Power and the City of Joburg, are now owed more than R6-billion.
Investment Solutions economist Chris Hart said the city could now be in the unenviable position of having to borrow money to cover the R2.8-billion lost.
"This could lead to a cash-flow crunch and the city could lose access to service providers where services are outsourced.
"It appears that the city is living beyond the payment means of its citizens," Hart said.
He added that the rating companies could downgrade the city's risk rating, forcing it to pay a lot more interest on its debt.
CharlesDarwin