Argentina's central bank could hike the benchmark interest rate to 75% this month, a source with direct knowledge of the board's discussions said on Thursday, in a bid to support the embattled peso currency amid one of the world's highest inflation rates.

That would be a 550 basis point jump from the current level of 69.5%.

The source, who declined to be identified as the talks were private, said that the rate hike would depend on consumer price index (CPI) rises, with annualized inflation running at over 70% and estimated to reach over 90% by the end of the year.

"The evolution of retail prices is being closely followed, and another hike in the rate is not ruled out to go with the upcoming (CPI) data for August, so that it can beat inflation," an adviser to the central bank told Reuters.

"It is an issue that is discussed within the board and no decision has been made, but it would not be unreasonable if the rate could rise to 75%," the source added.

A central bank spokesman declined to comment.

The central bank has sharply raised the 28-day 'Leliq' in recent months, with raises of 800 and 950 bps, coming after regular smaller adjustments earlier in the year.

Three analysts told Reuters they expected a hike this month of between 400 and 600 bps, against monthly inflation in August projected at 6%-6.5%. August inflation data will be released on Sept. 14.