Ancient bones buried beneath Oxford's Bonn Square could delay an ambitious redevelopment plan.

An artists' impression of one way of revamping of Bonn Square

The city council has released artists' impressions of two possible proposals and is now consulting the public on which they prefer.

It has committed £86,000 to the project and is considering adding a further £165,000 to fund the work to either flatten the square or provide a landscaped raised area.

If the council decides to go ahead with flattening the square, the most expensive option, it will have to deal with the delicate matter of removing bones from the 14th century burial site belo. It has to consult the Church of England's Oxford Diocese about any proposals to disturb the bones because the land is consecrated ground. Among the options are reburial, cremation, or arranging for the bones to go into the care of a museum. The Rev Richard Thomas, spokesman for the Oxford Diocese, warned that the council would have to apply to the Chancellor of the Diocese, Judge Rupert Bursell QC, for a faculty to disinter the bones.

Mr Thomas said: "It is not a foregone conclusion that a faculty would be granted and if it was not, then it could cause a delay or a rethink."

Roger Elkins, Bonn Square project manager for the city council, said: "We have involved the Church from day one, seeking their advice and permission for the archaeological dig, which has already taken place.

"We are now consulting the public on options for the square and when we have firm plans we will go back to the Diocese advisory committee for their advice. The Church has been extremely supportive of the principle of redeveloping Bonn Square and the council will of course respect their wishes regarding this burial site."