Thousands have de-registered Scottish Government's Protect Scotland app in last three months.
Whistleblower tells STV News that employees on the service are 'overworked, not properly trained and stressed'.
The Protect Scotland app has already told more than 100 Scots to self-isolate, Nicola Sturgeon revealed.
First Minister Nicola Sturgeon slammed the 'despicable' scammers.
The 'Protect Scotland' anonymously uses bluetooth technology to identify close contacts of coronavirus cases.
The 'Protect Scotland' proximity app which aims to help fight the spread of Covid-19 is available for free download.
The NHS programme is designed to reduce the risk of the virus spreading.
The First Minister said contact tracing has been completed on 481 positive coronavirus cases.
The Scottish Government had set a target of having 2000 tracers by the end of May to support its mass Covid-19 testing regime.
Scotland's test, trace and isolate regime will go live on Thursday, Nicola Sturgeon said.