The incident happened when the manager of Toots Takes All bookmakers was threatened and ordered to hand over money.
On Friday evening the Lifford betting shop received a phone call. A staff member was told to place a large sum of money in a bag.
A taxi then came and collected the sum of money the following morning and delivered it to a location near the border.
Gardai say the manager of the betting shop and the taxi driver were told that their lives would be in danger if they did not follow the orders.
The manager of the betting shop and the taxi driver were also warned not to contact gardai until the money was handed over.
It's understood that around €4,000 was taken.
The taxi which was used during the incident has been forensically examined and CCTV footage is being examined.
A similar extortion took place at the same premises in October, 2012.