(AGI) - Cape Town, Aug 24 - South Africa's Finance Minister Pravin Gordhan faces possible arrest after having been ordered to report to the country's elite police division, the Hawks, over allegations relating to a covert tax unit. The Hawks is investigating a tax surveillance unit within the South African Revenue Service (Sars) set up in 2007 when Gordhan was the commissioner of the revenue authority. The police unit is questioning whether the undercover investigation unit performed illegal activities. Online news agency The Daily Maverick last night broke the news that Gordhan has been asked to report to the Hawks at 10am on Thursday. It said that former Sars deputy commissioner Ivan Pillay, group executive Johann van Loggerenberg and initial head of the investigative unit, Andries van Rensburg were also asked to report to the Hawks. The country's National Treasury Department today confirmed that the Hawks have contacted Gordhan. Phumza Macanda of the Treasury Department said Gordhan received correspondence from the Hawks yesterday "but he is currently taking legal advice and will reserve comment at this stage". South Africa's currency, the rand, fell nearly three percent to the dollar after the news broke. Economists said South Africa's efforts to stave off a ratings downgrade have been dealt a major blow as the market sees Gordhan as key to South Africa's fiscal reform and his removal from this position will likely raise the possibility of a ratings downgrade to junk status. Ratings agencies Fitch, Moody's and Standard & Poor have resisted downgrading South Africa's credit rating during its rating reviews this year, deciding to keep the country's status above non-investment grade or junk status. However, they warned that South Africa needed to address its political and growth concerns. "If Gordhan was to go, I think there has to be a very real chance that we will be downgraded in December," said Umkhulu Consulting's Adam Phillips. "Maybe they won't wait to put us out of our misery. There is also the danger that any attack on the finance minister can plunge the country into the same sort of economical upheaval that it experienced when President Jacob Zuma removed Nhlanhla Nene as then finance minister in December last year. At the time, the rand fell to record lows against the US dollar, British pound and the Euro.as investors showed their displeasure with the move. Gordhan succeeded Nene as finance minister. (AGI) .