The arrest of an man with epilepsy in Ballymoney is being investigated by the police ombudsman.
It is alleged that Melvyn Graham, 46, was handcuffed while he was having a seizure on the Frosses Road last month.
His sister, Mandy, said the police may have mistaken Melvyn for a drunk or a drug abuser and he had suffered nerve damage in his wrists.
The PSNI said officers, using minimum force, restrained a person suffering from a known medical condition. "It is understood the ambulance staff later conveyed the man to his home when his condition improved and restraint was no longer required," said the PSNI.
The family said Melvyn had suffered epileptic seizures all his life and has had to be resuscitated on numerous occasions. Mandy Graham said on the day in question her brother remembered someone asking him what he had been taking.
"After that he cannot remember. He minds seeing the handcuffs," she said. But he cannot remember them being actually on him. We only have the physical marks and the damage done to the wrists that they'd definitely been there.
Solicitor Derwin Harvey said Mr Graham, who he described as a "vulnerable individual", was considering seeking compensation from police. He said most people in Ballymoney would be aware of his client's seizures and how to treat him. "They were very shocked and very angry that the police appear to have handcuffed him when he suffered a seizure on 25th June," he said.
As a result of handcuffing Melvyn, he has sustained quite serious injuries to his wrist as the handcuffs were applied when he was suffering from a seizure. Mr Harvey said police officers should be able to differentiate between a person having a seizure from someone who is on drugs. "The police have a duty of care to members of the public, especially vulnerable members of the public," he said.
"So the family are very angry if it is the case that they have applied handcuffs to him when he is in the middle of a seizure. It should have been apparent to the police that to take that course of action they were putting Melvyn at the risk of causing himself serious injury."
A spokesperson for the police ombudsman, Al Hutchinson, said: "We can confirm that we have received a complaint in relation to an allegation of assault."
" I am outraged by the senseless act of the police officers. I cannot imagine my hands being handcuffed during a seizure. Likelihood is I would have broken wrist bones because of my osteopinia condition. So often, I hear and read of news about police personels acting in uncivic and inappropriate ways when handling members of the public. The basic role of a police is to protect and safeguard people and not to unknowingly and carelessly harm people instead. "