According to the calculations of five bankers, based on data from the central bank and the sector, the fall in gross reserves amounted to between $4.8 billion and $6.1 billion last week, with an average forecast of some $5.4 billion.
The bankers said the forex demand had shown a clear rise in recent weeks ahead of the May 14 presidential and parliamentary elections, where President Tayyip Erdogan is facing the biggest political challenge of his two decades in power.
The Turkish lira has weakened some 3.1% against the dollar since devastating earthquakes in early February. It was slightly weaker at 19.4125 at 0600 GMT.
The central bank data showed that gross reserves, which are the sum of gold and forex reserves, fell to $121.5 billion by April 14 from $129.63 billion on Feb. 3.
A clear fall in net reserves was also expected, but not as big as the fall in gross reserves, according to the calculations.
The official central bank reserves data for last week was scheduled to be released on Thursday at 1130 GMT.
(Reporting by Nevzat Devranoglu; Editing by Daren Butler)
