Police forces across the country have launched a campaign to tackle fraud related to Hajj.
Around 25,000 British Muslims make the pilgrimage to Mecca in Saudi Arabia each year and many will book their travel arrangements over the coming months.
Action Fraud - the UK's fraud reporting centre - was informed about 49 cases of Hajj fraud from April 2015 to last month.
The average loss was over £2,600 and hotspots for offending were London, Birmingham, Manchester and Blackburn.
But detectives believe the extent of the problem is much worse than the reported cases.
Some 16 forces are engaging with their local Muslim communities in a bid to raise awareness of fraud.
The campaign is being supported by the British Council of Hajjis, travel association Abta and Atol, a financial protection scheme from the Civil Aviation Authority.
City of London Police Commander Chris Greany said: "Many victims will have saved for years to be able to afford to travel to Saudi Arabia and as a result will be absolutely devastated when they find out that they have in fact been conned by fraudsters."
People booking package trips with flights for Hajj this autumn are advised to make sure the company is covered by the Atol scheme to offer protection against losses if it goes bust.
They are also warned against paying by cash or direct bank transfer into an individual's account, to get everything in writing and to check flight details, accommodation and Hajj visas are valid.
Mark Rayner, Atol's head of compliance, commented: "It is really important that anyone looking to travel to Mecca this September as part of a Hajj pilgrimage looks beyond the price, checks that the travel business has Atol protection and ensures they receive an Atol certificate once they pay any money towards their trip."
Hajj is the annual pilgrimage to Mecca, the birthplace of Islam.