The family of a man from Sierra Leone who died in police custody in Fife a year ago this week have suggested that race may have “played a part” in the case.

Father-of-two Sheku Bayoh, 31, died on Sunday, May 3, after being restrained by officers responding to a call shortly after 7am about a man behaving erratically.

Officers involved in the arrest used CS spray and police batons before Bayoh was brought to the ground, face down, handcuffed and his legs restrained.

Within 10 minutes, Bayoh lost consciousness, stopped breathing and by the time he arrived at hospital he was unresponsive. He was pronounced dead at 9.04am.

Two officers later said they believed they may have been responding to a terrorist incident. It was also reported that one officer admitted to being racist in the weeks after Bayoh’s death.

Speaking ahead of a memorial service in Kirkcaldy today to mark a year on since his death, Bayoh’s sister Kadi Johnson, 38, raised the prospect that racism may be a factor.

She said: “We feel that maybe because we are black that’s why things have gone this way...I think the colour of our skin plays a part in this.”

The family will lay flowers at the scene of the incident in Hayfield Road, Kirkcaldy, at 1.30pm, before gathering at Templehall Community Centre at 2pm.

Johnson is expected to call for watchdog, the Police Investigation and Review Commissioner (Pirc), to release its findings to the Lord Advocate. She said: “We were expecting the report at the beginning of the year and we’re into May now. That has caused a lot of pain for the family. We cannot grieve properly for our brother. We had no faith in the Pirc anyway, and the delay is just making things worse now.”

Johnson, her husband, Ade, her sisters, Adama Jalloh and Kosna Bayoh, Sheku’s Mother Aminata Bayoh, Bayoh’s partner, Collette Bell, and the family’s solicitor, Aamer Anwar, will meet the Lord Advocate tomorrow.

Referring to the suggestion of racism, Anwar said: “I think the family are entitled to ask that question.”

A mandatory fatal accident inquiry (FAI) will be held to establish the circumstances of the death but Anwar and Bayoh’s family want a public enquiry.

Anwar said: “If there is just an FAI which doesn’t look at the elephant in room – the issue of race – which doesn’t look at the systemic failures...then it will send out a message.”

Johnson added: “I think they should go further than an FAI. Lessons need to be learned. People need to be punished for their actions...justice needs to be done. We need to know the truth...and we need closure so that we can grieve properly for our brother.”

Chairman of the Scottish Police Federation Brian Docherty dismissed suggestions of racism in the force.

He added: “We’re looking for an early FAI so that all the facts and circumstances can be presented in the public domain so that people can make their own minds up. It’s unhelpful, some of the innuendo and insinuations that are going on around about the case.

“Once the FAI comes out that should hopefully allow people to make their own mind up from there. I wasn’t there, I don’t know. I would rather that the information comes out in the FAI and, if there’s blame to be apportioned, I’ve absolutely no doubt whoever heads that inquiry will apportion that blame.”

Assistant Chief Constable Kate Thomson said Police Scotland is unable to respond to “specific issues or questions raised” while an investigation is ongoing.

“Our thoughts remain with Sheku Bayoh’s family and friends,” she added. “We also continue to offer support to anyone affected by this incident including the family of Sheku Bayoh, colleagues within the service and the communities we serve.”

A spokesman for the Pirc said the commissioner is “committed to getting to the truth of what happened” and has offered support to Bayoh’s family.

It is understood Pirc’s findings will be with the Lord Advocate in a matter of weeks rather than months. The spokesman added: “This is a complex and wide-ranging investigation and, as it has progressed, further lines of enquiry have emerged which have lengthened the investigative process.

“It is appropriate that all of these matters are rigorously explored to ensure a comprehensive investigation is undertaken.

“The commissioner continues to act on the instructions of the Lord Advocate and is committed to delivering a thorough, impartial and independent investigation.”