A patient who demanded to be seen by a "white doctor" at A&E and was turned away, then submitted a formal complaint to the hospital over their refusal.
He added that the patients has now been "excluded" and said they are considering reporting the matter to the police.
"This was hugely upsetting for the staff involved - appalling," Mr Foster said.
When asked how the trust would respond to the incident, Mr Foster said: "We will exclude this individual."
"I am exploring whether the police will take a role in this too. I cannot believe the nerve of submitting a formal complaint against the hospital!"
NHS organisations can place exclusion orders to blacklist patients who are violent or abusive to staff and other patients.
This will not prevent them obtaining emergency treatment but may mean they have to attend another trust for routine care and security may turn them away.
The NHS staff survey revealed around 30 per cent of its 1.2million staff have been abused by patients or their families, but black and ethnic minority workers experience abuse it at a much higher rate.
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