An agent has apparently closed and is said to owe landlords and tenants money in rent and deposits.
The firm is Kirby Property Management, with three branches in Cambridgeshire.
The firm belonged to both NALS and TDS.
NALS told EYE that it is aware of the case.
A spokesperson said: “We are aware of the sudden closure of Kirby Property Management who were previously part of the National Approved Letting Scheme.
“We would advise any landlords or tenants who have any concerns to speak with Cambridgeshire police in the first instance.
“Landlords may also wish to register their interest with NALS who operate a Client Money Protection scheme and may, in certain circumstances, be able to assist.”
We also asked TDS to comment.