Dependability Limited used a test on people with complex health issues which wasn't fit for purpose.
That's according to evidence given to a Social Affairs Policy Review Committee yesterday.
It was reviewing the Personal Capability Assessments carried out by the external company - an independent report looking at the process was also considered.
The controversial assessments - which determined whether a person was eligible for incapacity benefits - were dumped by the Treasury last year.
Victoria McLauchlan is the deputy director of operations in social security - she told the committee it's clear something didn't work:
Stop putting knives in recycling, says council
Bee Gees to release limited-edition box set
Northern Irish politician criticises Manx visa rules
Elective surgical unit opens at hospital
Piling rig on TT course tonight
10-day bus strike from next weekend
Yellow snow warning issued by forecasters
Ramsey harbour keeper completes 3,000-Mile Atlantic crossing