At least three tents have been spotted in woodland next to the online retailer’s giant distribution depot in Scotland.
It has also recently emerged workers have been fined for taking time off sick.
But Amazon dismissed the claims and said it values its employees at its site in Dunfermline, Fife.
A worker said to be staying in a tent claimed the firm was a “poor employer” and criticised its working practices.
He also said staying in a tent was easier and cheaper than commuting from Perth.
Scottish Liberal Democrat leader Willie Rennie has criticised Amazon, and said they should be “ashamed”.
He said: “Amazon should be ashamed that they pay their workers so little that they have to camp out in the dead of winter to make ends meet. Amazon need to take a long, hard look at themselves and change their ways.
“They pay a small amount of tax and received millions of pounds from the SNP Government so the least they should do is pay the proper living wage.
“The fares the company charge for transport swallow up a lot of the weekly wage which is forcing people to seek ever more desperate ways of making work pay.”
Four thousand new positions have been created over the festive season at Amazon as they deal with the Christmas rush.
Temporary workers are being drafted in on coaches from Glasgow, Dundee and Stirling.
It is understood the company charges £10 a day for transport.
An spokeswoman for Amazon said: “Amazon provides a safe and positive workplace. The safety and wellbeing of our permanent and temporary associates is our number one priority.
“We are also proud to have been able to create several thousand new permanent roles in our UK fulfilment centres over the last five years.
“We pay competitive wages - all permanent and temporary Amazon associates start on £7.35 an hour or above regardless of age and £11 an hour and above for overtime.”