The SABC is owed over R1-billion for advertisements flighted but not paid for.

Responding to written questions by the DA, Communications Minister Dina Pule said the national broadcaster was owed R1-billion by all three tiers of the government, as well as by advertising agencies and companies.

"Total debt to the SABC at the end of March was more than R1-billion from more than 3000 accounts," said Pule.

Those who owe the SABC, including government departments, could be sued.

Pule would not say how much the state owed the SABC. She said negotiations were under way to determine how the bill could be settled, but she did not rule out litigation.

She said, however, that should the SABC take legal action all other means to settle the debt would prove "fruitless". Legal action is already pending on a number of accounts, she said.

"As is the case with other significant advertisers, arrears occur from time to time and are mostly related to disputes or cash-flow difficulties," she said.

SABC spokesman Kaizer Kganyago confirmed that the government owed money to the SABC.

But he said the government advertising debt accounted for only a "fraction" of the R1-billion owed.

He refused to say exactly how much the government owed the SABC, claiming such information was privileged.

"It is not only from the government but all the state entities that owe us. This includes more than 3000 accounts. The status of these accounts changes from time to time as we have a unit that deals with the recovery of all the money.

"This is a dynamic process which we are handling. We are therefore not in a position to divulge the institutions that owe us as this is privileged information," Kganyago said.

Earlier this year, the SABC appealed to parliament to relax the stringent performance-based conditions attached to a R1.4-billion loan from the Treasury.

This was to help it weather the 2009 financial crisis.

Conditions of the loan included that the SABC raise its advertising revenue by R535-million next year and sponsorship revenue by R128-million in the same period.