SEMA, who used to run the Benefits Agency Medical Services (BAMS) contract before ATOS were thought to have used doctors who treated claimants badly including with a degree of racism - see the exchange from the House of Lords (24th May 2000). If you read the full evidence of the 2000 select committee report, it is clear that some of the sessional doctors eg acted as if claimants with Irish backgrounds were drunkards, were offensive to Asian claimants etc. I think a number of the sessional doctors were not top drawer - semi retired, semi employed etc.

ATOS essentially took over many of SEMA's operations and staff, afaik, so maybe surprising more allegations like this haven't surfaced yet



(From House of Lords 24th May)
“Lord Ashley of Stoke
My Lords, I am grateful for that reply. Is my noble friend aware that the Select Committee was scathing about the private medical agency, the SEMA Group, which is used by the Benefits Agency to examine sick and disabled people who claim benefit? The Select Committee accused that group of imposing on sick and disabled people unacceptable delays, painful examinations, rude treatment and racial discrimination? Is my noble friend aware that, although the recommendations of the Select Committee are welcome, in my view they are wholly inadequate and the Government need to reconsider the use of these private medical agencies and certainly should get rid of the SEMA Group which is responsible for so much distress to many sick and disabled people?
Baroness Hollis of Heigham
My Lords, the Government will publish their response to the report of the Select Committee at the end of June. My colleagues in the other place and officials are working on that response. I do not for a moment dissociate myself from some of the comments made in the report. The Government accept the criticism that some of the 3,000 part-time and sessional doctors, not so much the 250 full-time doctors who were with the original Benefits Agency Medical Service (BAMS) when it transferred over, have exhibited the behaviour described by my noble friend. It is quite clear that some doctors have been somewhat crass in their response to patients' needs. I believe that the right response to that is that advocated by the Select Committee, which is significantly to increase the training available to doctors, particularly part-time ones. After all, those doctors provide advice on about £25 billion of benefit. As a result, it is crucial that we get the most highly qualified and best trained doctors to deal with a very sensitive area of medicine. That is why the proposals made by the Select Committee in terms of improving the training of doctors, the auditing of their reports and so on are being taken seriously by government. “