|The caves could have been used as dormitories
for slaves a group claims.
The Sparkbrook Caribbean and African Women's Development Initiative (SCAWDI) claims three carvings in caves alongside Guy's Cliffe House, near Warwick, were made by slaves in the 17th Century and deserve to be preserved for the nation.
"I haven't seen anything like it outside Africa. It's the only one of its kind in Europe," Barbara Willis-Brown, director of SCAWDI, said.
Ms Willis-Brown added: "In 1751, Samuel Greatheed returned from his plantations in St Kitts and started to build the house.
"A noted slave trader, we believe, rather than pay wages, he brought slaves over to help in its construction."
Ms Willis-Brown said Samuel Greatheed was one of the most prominent slave traders in the Caribbean and later received the large sum of £25,000 in compensation from the government following the abolition of the slave trade.'Incredibly important'
She added: "The caves would probably have been used as dormitories.
"They're obviously Negro features. We think they carved their faces here, hoping they would be found one day."
If true, Ms Willis-Brown said that the carvings would be a "rare" and "incredibly important" reminder of Britain's black heritage.
Carved into the soft chalk-stone, Ms Willis-Brown said the carvings were in a poor condition.
Currently in private ownership there is no general public access to the caves.
Guys Cliffe House itself is currently owned by a Masonic lodge, whose spokesman Derek Maudlin said: "I've looked at them and thought they were knights' helmets."Shipping records
He added: "What I would like to see is for SCAWDI to present us with the evidence for their claims and once convinced by that evidence we would want to work with them and English Heritage to see where we could go.
"The whole of it I think would need to be established by some form of archaeological investigation."
According to the county record office, it was not unusual for some landed families to bring slaves over to Britain, with several records of them being freed, baptised and buried in the 18th and 19th Centuries.
Archivists at the record office said that while no explicit evidence had been discovered of slaves being brought to the Guy's Cliffe estate, it remained a "strong possibility".
SCAWDI said it was hoping to raise money for an archaeological excavation, after the Heritage Lottery Fund said it would not make grants to sites inaccessible to the public.
First made aware of the caves three years ago, SCAWDI said the search was still on for conclusive proof of the Warwickshire slaves.
The organisation said it was going through shipping records to the major slave ports, Liverpool, Bristol and Whitehaven, a task Ms Willis-Brown claimed could take years.