Nantwich Travel joined Global earlier this year having previously been part of the Worldchoice consortium.
Customers allege that the holidays they paid for have not been booked.
According to website Company Check, David Shearer is the proprietor of the business.
In a statement a spokesperson for Global said: “The Global Travel Group is supporting the police with their enquiries regarding Nantwich Travel.
“We are saddened to learn of any possible misconduct.
“We urge anyone who is concerned about a holiday booking, or any payment they made to Nantwich Travel, to contact the police directly.
“We are unable to comment further on an ongoing police investigation.”
Although the company’s shop front shows the Abta logo, a spokesperson said its membership ended a number of years ago.
Gary Lewis, group managing director, The Travel Network Group, said: "Nantwich Travel was removed from being a member of ours in April 2015.
"However, as part of the Travel Trust Association’s unique 100% financial protection package, we have honoured all passengers that had paid money to Nantwich Travel up to the 25th April.
"This has covered 250 passengers to date. We would always advise members of the public when booking their holidays to book with a reputable company that offers financial protection such as the Travel Trust Association or a company within the CAA ATOL protection scheme."
Police have been alerted to the apparent closure of a travel agent in Cheshire after angry customers alleged that the bookings they made do not exist.
A holidaymaker, who did not want to be named, told The Crewe Chronicle: “We are devastated. This was supposed to be a once in a lifetime holiday for my family, for my children to Orlando Florida. My two little girls wanted to go and see Mickey Mouse in Disneyland. I have lost £3,200. We booked the holiday on January 26.”
He added: “I spoke to David Shearer yesterday and he promised that he would refund money into my account but that has not happened. I have filed a complaint with Nantwich Police Station. I believe Crewe CID are dealing with it now.”
TTG called Nantwich Travel but there was no answer.